High performance selective light wavelength filtering

ABSTRACT

A system may be provided that comprises a substrate and a selective light wavelength filter that selectively blocks between 5 and 50% of light having a wavelength at or near 400-460 nm. The system may comprise any one of, or some combination of: a window, automotive glass, a light bulb, a flash bulb, fluorescent lighting, LED lighting, instrumentation, a display system, a visual system, a television, or a computer monitor.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/360,264 filed Jan. 27, 2012. U.S. patent application Ser. No.13/360,264 is a continuation of U.S. patent application Ser. No.12/037,565 filed Feb. 26, 2008, which claims the benefit of U.S.Provisional Applications 60/903,324 filed Feb. 26, 2007 and 60/906,205filed Mar. 12, 2007. U.S. patent application Ser. No. 12/037,565 is acontinuation-in-part of U.S. patent application Ser. No. 11/933,069filed Oct. 31, 2007, which claims priority to U.S. ProvisionalApplication 60/978,175 filed Oct. 8, 2007. U.S. patent application Ser.No. 11/933,069 is a continuation-in-part of U.S. patent application Ser.No. 11/892,460 filed Aug. 23, 2007, which claims priority to U.S.Provisional Applications 60/839,432 filed Aug. 23, 2006; 60/841,502filed Sep. 1, 2006; and 60/861,247 filed Nov. 28, 2006. U.S. patentapplication Ser. No. 11/933,069 is a continuation-in-part of U.S. patentapplication Ser. No. 11/761,892 filed Jun. 12, 2007, which claimspriority to U.S. Provisional Application 60/812,628 filed Jun. 12, 2006and is a continuation-in-part of U.S. patent application Ser. No.11/378,317 filed Mar. 20, 2006. All of these applications are entirelyincorporated by reference.

BACKGROUND OF THE INVENTION

Electromagnetic radiation from the sun continuously bombards the Earth'satmosphere. Light is made up of electromagnetic radiation that travelsin waves. The electromagnetic spectrum includes radio waves, millimeterwaves, microwaves, infrared, visible light, ultra-violet (UVA and UVB),x-rays, and gamma rays. The visible light spectrum includes the longestvisible light wavelength of approximately 700 nm and the shortest ofapproximately 400 nm (nanometers or 10⁻⁹ meters). Blue light wavelengthsfall in the approximate range of 400 nm to 500 nm. For the ultra-violetbands, UVB wavelengths are from 290 nm to 320 nm, and UVA wavelengthsare from 320 nm to 400 nm. Gamma and x-rays make up the higherfrequencies of this spectrum and are absorbed by the atmosphere. Thewavelength spectrum of ultraviolet radiation (UVR) is 100 nm to 400 nm.Most UVR wavelengths are absorbed by the atmosphere, except where thereare areas of stratospheric ozone depletion. Over the last 20 years,there has been documented depletion of the ozone layer primarily due toindustrial pollution. Increased exposure to UVR has broad public healthimplications as an increased burden of UVR ocular and skin disease is tobe expected.

The ozone layer absorbs wavelengths up to 286 nm, thus shielding livingbeings from exposure to radiation with the highest energy. However, weare exposed to wavelengths above 286 nm, most of which falls within thehuman visual spectrum (400-700 nm). The human retina responds only tothe visible light portion of the electromagnetic spectrum. The shorterwavelengths pose the greatest hazard because they inversely contain moreenergy. Blue light has been shown to be the portion of the visiblespectrum that produces the most photochemical damage to animal retinalpigment epithelium (RPE) cells. Exposure to these wavelengths has beencalled the blue light hazard because these wavelengths are perceived asblue by the human eye.

Cataracts and macular degeneration are widely thought to result fromphotochemical damage to the intraocular lens and retina, respectively.Blue light exposure has also been shown to accelerate proliferation ofuveal melanoma cells. The most energetic photons in the visible spectrumhave wavelengths between 380 and 500 nm and are perceived as violet orblue. The wavelength dependence of phototoxicity summed over allmechanisms is often represented as an action spectrum, such as isdescribed in Mainster and Sparrow, “How Much Blue Light Should an IOLTransmit?” Br. J. Ophthalmol., 2003, v. 87, pp. 1523-29 and FIG. 6. Ineyes without an intraocular lens (aphakic eyes), light with wavelengthsshorter than 400 nm can cause damage. In phakic eyes, with someintraocular devices, this light is absorbed by the intraocular lens andtherefore does not contribute to retinal phototoxicity; however it cancause optical degradation of the lens or cataracts.

The pupil of the eye responds to the photopic retinal illuminance, introlands, which is the product of the incident flux with thewavelength-dependent sensitivity of the retina and the projected area ofthe pupil. This sensitivity is described in Wyszecki and Stiles, ColorScience: Concepts and Methods. Quantitative Data and Formulae (Wiley:New York) 1982, esp. pages 102-107.

Current research strongly supports the premise that short wavelengthvisible light (blue light) having a wavelength of approximately 400nm-500 nm could be a contributing cause of AMD (age related maculardegeneration). It is believed that the highest level of blue lightabsorption occurs in a region around 430 nm, such as 400 nm-460 nm.Research further suggests that blue light worsens other causativefactors in AMD, such as heredity, tobacco smoke, and excessive alcoholconsumption.

High energy blue/violet light, e.g., light having wavelengths of about400 nm to about 470 nm, either by itself or in combination withultraviolet light, may contribute to oxidative changes within the humancrystalline lens resulting in presbyopia. Presbyopia is the loss of theability (or accommodative amplitude) of the human crystalline lens tofocus at near, point. This loss of accommodation begins at infancy andincreases throughout life, but it goes unnoticed by the individual untilaround age 40-45 years when he or she experiences near-point blur whenviewing a near-point object. Today, presbyopia affects an estimated 1.6billion people worldwide, and this number is expected to increase as thepopulation ages.

The human retina includes multiple layers. These layers listed in orderfrom the first exposed to any light entering the eye to the deepestinclude:

1) Nerve Fiber Layer

2) Ganglion Cells

3) Inner Plexiform Layer

4) Bipolar and Horizontal Cells

5) Outer Plexiform Layer

6) Photoreceptors (Rods and Cones)

7) Retinal Pigment Epithelium (RPE)

8) Brach's Membrane

9) Choroid

When light is absorbed by the eye's photoreceptor cells, (rods andcones) the cells bleach and become unreceptive until they recover. Thisrecovery process is a metabolic process and is called the “visualcycle.” Absorption of blue light has been shown to reverse this processprematurely. This premature reversal increases the risk of oxidativedamage and is believed to lead to the buildup of the pigment lipofuscinin the retina. This build up occurs in the retinal pigment epithelium(RPE) layer. It is believed that aggregates of extra-cellular materialscalled drusen are formed due to the excessive amounts of lipofuscin.

Current research indicates that over the course of one's life, beginningwith that of an infant, metabolic waste byproducts accumulate within thepigment epithelium layer of the retina, due to light interactions withthe retina. This metabolic waste product is characterized by certainfluorophores, one of the most prominent being lipofuscin constituentA2E. In vitro studies by Sparrow indicate that lipofuscin chromophoreA2E found within the RPE is maximally excited by 430 nm light. It istheorized that a tipping point is reached when a combination of abuild-up of this metabolic waste (specifically the lipofuscinfluorophore) has achieved a certain level of accumulation, the humanbody's physiological ability to metabolize within the retina certain ofthis waste has diminished as one reaches a certain age threshold, and ablue light stimulus of the proper wavelength causes drusen to be formedin the RPE layer. It is believed that the drusen then further interferewith the normal physiology/metabolic activity which allows for theproper nutrients to get to the photoreceptors thus contributing toage-related macular degeneration (AMD). AMD is the leading cause ofirreversible severe visual acuity loss in the United States and WesternWorld. The burden of AMD is expected to increase dramatically in thenext 20 years because of the projected shift in population and theoverall increase in the number of ageing individuals.

Drusen hinder or block the RPE layer from providing the proper nutrientsto the photoreceptors, which leads to damage or even death of thesecells. To further complicate this process, it appears that whenlipofuscin absorbs blue light in high quantities it becomes toxic,causing further damage and/or death of the RPE cells. It is believedthat the lipofuscin constituent A2E is at least partly responsible forthe short-wavelength sensitivity of RPE cells. A2E has been shown to bemaximally excited by blue light; the photochemical events resulting fromsuch excitation can lead to cell death. See, for example, Janet R.Sparrow et al., “Blue light-absorbing intraocular lens and retinalpigment epithelium protection in vitro,” J. Cataract Refract. Surg.2004, vol. 30, pp. 873-78.

From a theoretical perspective, the following appears to take place:

1) Waste buildup occurs within the pigment epithelial level startingfrom infancy through out life.

2) Retinal metabolic activity and ability to deal with this wastetypically diminish with age.

3) The macula pigment typically decreases as one ages, thus filteringout less blue light.

4) Blue light causes the lipofuscin to become toxic. The resultingtoxicity damages pigment epithelial cells.

The lighting and vision care industries have standards as to humanvision exposure to UVA and UVB radiation. Surprisingly, no such standardis in place with regard to blue light. For example, in the commonfluorescent tubes available today, the glass envelope mostly blocksultra-violet light but blue light is transmitted with littleattenuation. In some cases, the envelope is designed to have enhancedtransmission in the blue region of the spectrum. Such artificial sourcesof light hazard may also cause eye damage. The inventors theorize thatthe combination of the ozone hole in the atmosphere, numerous near-pointtasks such as working on a computer, various artificial lightingincluding specifically florescent tubes and blue diodes, televisionsets, and even camera flashes contribute to the proliferation ofdamaging wavelengths of UV and high energy blue (blue/violet) light.

Laboratory evidence by Sparrow at Columbia University has shown that ifabout 50% of the blue light within the wavelength range of 430±20 nm isblocked, RPE cell death caused by the blue light may be reduced by up to80%. External eyewear such as sunglasses, spectacles, goggles, andcontact lenses that block blue light in an attempt to improve eye healthare disclosed, for example, in U.S. Pat. No. 6,955,430 to Pratt. Otherophthalmic devices whose object is to protect the retina from thisphototoxic light include intraocular and contact lenses. Theseophthalmic devices are positioned in the optical path betweenenvironmental light and the retina and generally contain or are coatedwith dyes that selectively absorb blue and violet light.

Other lenses are known that attempt to decrease chromatic aberration byblocking blue light. Chromatic aberration is caused by opticaldispersion of ocular media including the cornea, intraocular lens,aqueous humour, and vitreous humour. This dispersion focuses blue lightat a different image plane than light at longer wavelengths, leading todefocus of the full color image. Conventional blue blocking lenses aredescribed in U.S. Pat. No. 6,158,862 to Patel et al., U.S. Pat. No.5,662,707 to Jinkerson, U.S. Pat. No. 5,400,175 to Johansen, and U.S.Pat. No. 4,878,748 to Johansen.

Conventional methods for reducing blue light exposure of ocular mediatypically completely occlude light below a threshold wavelength, whilealso reducing light exposure at longer wavelengths. For example, thelenses described in U.S. Pat. No. 6,955,430 to Pratt transmit less than40% of the incident light at wavelengths as long as 650 nm, as shown inFIG. 6 of Pratt '430. The blue-light blocking lens disclosed by Johansenand Diffendaffer in U.S. Pat. No. 5,400,175 similarly attenuates lightby more than 60% throughout the visible spectrum, as illustrated in FIG.3 of the '175 patent.

Balancing the range and amount of blocked blue light may be difficult,as blocking and/or inhibiting blue light affects color balance, colorvision if one looks through the optical device, and the color in whichthe optical device is perceived. For example, shooting glasses appearbright yellow and block blue light. The shooting glasses often causecertain colors to become more apparent when one is looking into a bluesky, allowing for the shooter to see the object being targeted soonerand more accurately. While this works well for shooting glasses, itwould be unacceptable for many ophthalmic applications. In particular,such ophthalmic systems may be cosmetically unappealing because of ayellow or amber tint that is produced in lenses by blue blocking. Morespecifically, one common technique for blue blocking involves tinting ordyeing lenses with a blue blocking tint, such as BPI Filter Vision 450or BPI Diamond Dye 500. The tinting may be accomplished, for example, byimmersing, the lens in a heated tint pot containing a blue blocking dyesolution for some predetermined period of time. Typically, the dyesolution has a yellow or amber color and thus imparts a yellow or ambertint to the lens. To many people, the appearance of this yellow or ambertint may be undesirable cosmetically. Moreover, the tint may interferewith the normal color perception of a lens user, making it difficult,for example, to correctly perceive the color of a traffic light or sign.

Efforts have been made to compensate for the yellowing effect ofconventional blue blocking filters. For example, blue blocking lenseshave been treated with additional dyes, such as blue, red or green dyes,to offset the yellowing effect. The treatment causes the additional dyesto become intermixed with the original blue blocking dyes. However,while this technique may reduce yellow in a blue blocked lens,intermixing of the dyes may reduce the effectiveness of the blueblocking by allowing more of the blue light spectrum through. Moreover,these conventional techniques undesirably reduce the overalltransmission of light wavelengths other than blue light wavelengths.This unwanted reduction may in turn result in reduced visual acuity fora lens user.

It has been found that conventional blue-blocking reduces visibletransmission, which in turn stimulates dilation of the pupil. Dilationof the pupil increases the flux of light to the internal eye structuresincluding the intraocular lens and retina. Since the radiant flux tothese structures increases as the square of the pupil diameter, a lensthat blocks half of the blue light but, with reduced visibletransmission, relaxes the pupil from 2 mm to 3 mm diameter, willactually increase the dose of blue photons to the retina by 12.5%.Protection of the retina from phototoxic light depends on the amount ofthis light that impinges on the retina, which depends on thetransmission properties of the ocular media and also on the dynamicaperture of the pupil. Previous work to date has been silent on thecontribution of the pupil to prophylaxis of phototoxic blue light.

Another problem with conventional blue-blocking is that it can degradenight vision. Blue light is more important for low-light level orscotopic vision than for bright light or photopic vision, a result whichis expressed quantitatively in the luminous sensitivity spectra forscotopic and photopic vision. Photochemical and oxidative reactionscause the absorption of 400 to 450 nm light by intraocular lens tissueto increase naturally with age. Although the number of rodphotoreceptors on the retina that are responsible for low-light visionalso decreases with age, the increased absorption by, the intraocularlens is important to degrading night vision. For example, scotopicvisual sensitivity reduced by 33% in a 53 year-old intraocular lens and75% in a 75 year-old lens. The tension between retinal protection andscotopic sensitivity is further described in Mainster and Sparrow, “HowMuch Light Should an IOL Transmit?” Br. J. Ophthalmol., 2003, v. 87, pp,1523-29.

Conventional approaches to blue blocking also may include cutoff orhigh-pass filters to reduce the transmission below a specified blue orviolet wavelength to zero. For example, all light below a thresholdwavelength may be blocked completely or almost completely. For example,U.S. Pub. Patent Application No. 2005/0243272 to Mainster and Mainster,“Intraocular Lenses Should Block UV Radiation and Violet but not BlueLight,” Arch. Ophthal., v. 123, p. 550 (2005) describe the blocking ofall light below a threshold wavelength between 400 and 450 nm. Suchblocking may be undesirable, since as the edge of the long-pass filteris shifted to longer wavelengths, dilation of the pupil acts to increasethe total flux. As previously described, this can degrade scotopicsensitivity, and increase color distortion.

Recently here has been debate in ‘the field of intraocular lenses(IOLs)’, regarding, appropriate UV and blue light blocking whilemaintaining acceptable photopic vision, scotopic vision, color vision,and circadian rhythms.

In view of the foregoing here is a need for an ophthalmic system thatcan provide one or more of the following:

1) Blue blocking with an acceptable level of blue light protection

2) Acceptable color cosmetics, i.e., it is perceived as mostly colorneutral by someone observing the ophthalmic system when worn by awearer.

3) Acceptable color perception for a user. In particular, there is aneed for an ophthalmic system that will not impair the wearer's colorvision and further that reflections from the back surface of the systeminto the eye of the wearer be at a level of not being objectionable tothe wearer.

4) Acceptable level of light transmission for wavelengths other thanblue light wavelengths. In particular, there is a need for an ophthalmicsystem that allows for selective blockage of wavelengths of blue lightwhile at the same time transmitting in excess of 80% of visible light.

5) Acceptable photopic vision, scotopic vision, color vision, and/orcircadian rhythms.

6) Improved contrast sensitivity and/or visual acuity.

This need exists as more and more data is pointing to blue light as oneof the possible contributory factors in macula degeneration (the leadingcause of blindness in the industrialized world) and also other retinaldiseases, including cataracts (the leading cause of blindness in thenon-industrialized world) and presbyopia.

BRIEF SUMMARY OF THE INVENTION

Embodiments disclosed herein relate to ophthalmic systems comprising aselective light wavelength filter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show examples of an ophthalmic system including aposterior blue blocking component and an anterior color balancingcomponent.

FIG. 2 shows an example of using a dye resist to form an ophthalmicsystem.

FIG. 3 illustrates an exemplary system with a blue blocking componentand a color balancing component integrated into a clear or mostly clearophthalmic lens.

FIG. 4 illustrates an exemplary ophthalmic system formed using anin-mold coating.

FIG. 5 illustrates the bonding of two ophthalmic components.

FIG. 6 illustrates exemplary ophthalmic systems using anti-reflectivecoatings.

FIGS. 7A-7C illustrate various exemplary, combinations of a blueblocking component, a color balancing component, and an ophthalmiccomponent.

FIGS. 8A and 8B show examples of an ophthalmic system including amulti-functional blue blocking and color-balancing component.

FIG. 9 shows a reference of observed colors that correspond to variousCIE coordinates.

FIG. 10 shows the transmission of the GENTEX E465 absorbing dye.

FIG. 11 shows the absorbance of the GENTEX E465 absorbing dye.

FIG. 12 shows the transmittance of a polycarbonate substrate with a dyeconcentration suitable for absorbing in the 430 nm range.

FIG. 13 shows the transmittance as a function of wavelength of apolycarbonate substrate with an antireflective coating.

FIG. 14 shows the color plot of a polycarbonate substrate with anantireflective coating.

FIG. 15 shows the transmittance as a function of wavelength of anuncoated polycarbonate substrate and a polycarbonate substrate with anantireflective coating on both surfaces.

FIG. 16 shows the spectral transmittance of a 106 nm layer of TiO2 on apolycarbonate substrate.

FIG. 17 shows the color plot of a 106 nm layer of TiO2 on apolycarbonate substrate.

FIG. 18 shows the spectral transmittance of a 134 nm layer of TiO2 on apolycarbonate substrate.

FIG. 19 shows the color plot of a 134 nm layer of TiO2 on apolycarbonate, substrate.

FIG. 20 shows the spectral transmittance of a modified AR coatingsuitable for color balancing a substrate having a blue absorbing dye.

FIG. 21 shows the color plot of a modified AR coating suitable for colorbalancing a substrate having a blue absorbing dye.

FIG. 22 shows the spectral transmittance of a substrate having a blueabsorbing dye.

FIG. 23 shows the color plot of a substrate having a blue absorbing dye.

FIG. 24 shows the spectral transmittance of a substrate having a blueabsorbing dye and a rear AR coating.

FIG. 25 shows the color plot of a substrate having a blue absorbing dyeand a rear AR coating.

FIG. 26 shows the spectral transmittance of a substrate having a blueabsorbing dye and AR coatings on the front and rear surfaces.

FIG. 27 shows the color plot of a substrate having a blue absorbing dyeand AR coatings on the front and rear surfaces.

FIG. 28 shows the spectral transmittance of a substrate having a blueabsorbing dye and a color balancing AR coating.

FIG. 29 shows the color plot of a substrate having a blue absorbing dyeand a color balancing AR coating.

FIG. 30 shows an exemplary ophthalmic device comprising a film.

FIG. 31 shows the optical transmission characteristic of an exemplaryfilm.

FIG. 32 shows an exemplary ophthalmic system comprising a film.

FIG. 33 shows an exemplary system comprising a film.

FIGS. 34A and B show pupil diameter and pupil area, respectively, as afunction of field illuminance.

FIG. 35 shows the transmission spectrum of a film that is doped withperylene dye where the product of concentration and path length yieldabout 33% transmission at about 437 nm.

FIG. 36 shows the transmission spectrum of a film with a peryleneconcentration about 2.27 tines higher than that illustrated in theprevious figure.

FIG. 37 shows an exemplary transmission spectrum for a six-layer stackof SiO₂ and ZrO₂.

FIG. 38 shows reference color coordinates corresponding to Munsell tilesilluminated by a prescribed illuminant in (L*, a*, b*) color space.

FIG. 39A shows a histogram of the color shifts for Munsell color tilesfor a related filter. FIG. 39B shows a color shift induced by a relatedblue-blocking filter.

FIG. 40 shows a histogram of color shifts for a perylene-dyed substrate.

FIG. 41 shows the transmission spectrum of a system combining dielectricstacks and perylene dye.

FIG. 42 shows a histogram summarizing color distortion of a device forMunsell tiles in daylight.

FIGS. 43A-43B show representative series of skin reflectance spectrafrom subjects of different races.

FIG. 44 shows an exemplary skin reflectance spectrum for a Caucasiansubject.

FIG. 45 shows transmission spectra for various lenses.

FIG. 46 shows exemplary dyes.

FIG. 47 shows an ophthalmic system having a hard coat.

FIG. 48 shows the transmittance as a function of wavelength for aselective filter with strong absorption band mound 430 nm.

FIG. 49A-E show embodiments of corneal inlays. FIG. 49A shows a cornealinlay with micro-apertures throughout the inlay. FIG. 49B shows acorneal inlay with a central zone and a peripheral region to create apinhole effect. FIG. 49C shows a corneal inlay with a curved and/orthickened peripheral region. FIG. 49D shows a corneal inlay having acentral zone with a plurality of pixel-like index changes. FIG. 49Eshows a corneal inlay having a static diffractive central zone.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments disclosed herein relate to an ophthalmic system thatperforms effective blue blocking while at the same time providing acosmetically attractive product, normal or acceptable color perceptionfor a user, and a high level of transmitted light for good visualacuity. An ophthalmic system is provided that can provide an averagetransmission of 80% or better transmission of visible light, inhibitselective wavelengths of blue light (“blue blocking”), allow for thewearer's proper color vision performance, and provide a mostly colorneutral appearance to an observer looking at the wearer wearing such alens or lens system. As used herein, the “average transmission” of asystem refers to the average transmission at wavelengths in a range,such as the visible spectrum. A system also may be characterized by the“luminous transmission” of the system, which refers to an average in awavelength range, that is weighted according to the sensitivity of theeye at each wavelength. Systems described herein may use various opticalcoatings, films, materials, and absorbing dyes to produce the desiredeffect.

More specifically, embodiments disclosed herein may provide effectiveblue blocking in combination with color balancing. “Color balancing” or“color balanced” as used herein means that the yellow or amber color, orother unwanted effect of blue blocking is reduced, offset, neutralizedor otherwise compensated for so as to produce a cosmetically acceptableresult, without at the same time reducing the effectiveness of the blueblocking. For example, wavelengths at or near 400 nm-460 nm may beblocked or reduced in intensity. In particular, for example, wavelengthsat or near 420-440 nm may be blocked or reduced in intensity.Furthermore, transmission of unblocked wavelengths may remain at a highlevel, for example at least 80%. Additionally, to an external viewer,the ophthalmic system may look clear or mostly clear. For a system,user, color perception may be normal or acceptable.

An “ophthalmic system” as used here includes prescription ornon-prescription ophthalmic lenses used, e.g., for clear or tintedglasses (or spectacles), sunglasses, contact lenses with and withoutvisibility and/or cosmetic tinting, intra-ocular lenses (IOLs), cornealgrafts, corneal inlays, corneal on-lays, and electro-active ophthalmicdevices and may be treated or processed or combined with othercomponents to provide desired functionalities described in furtherdetail herein. The system can be formulated so as to allow being applieddirectly into corneal tissue.

As used herein, an “ophthalmic material” is one commonly used tofabricate an ophthalmic system, such as a corrective lens. Exemplaryophthalmic materials include glass, plastics such as CR-39, Trivex, andpolycarbonate materials, though other materials may be used and areknown for various ophthalmic systems.

An ophthalmic system may include a blue blocking component posterior toa color-balancing component. Either of the blue blocking component orthe color balancing component may be, or form part of, an ophthalmiccomponent such as a lens. The posterior blue blocking component andanterior color balancing component may be distinct layers on or adjacentto or near a surface or surfaces of an ophthalmic lens. Thecolor-balancing component may reduce or neutralize a yellow or ambertint of the posterior blue blocking component, to produce a cosmeticallyacceptable appearance. For example, to an external viewer, theophthalmic system may look clear or mostly clear. For a system user,color perception may be normal or acceptable. Further, because the blueblocking and color balancing tints are not intermixed, wavelengths inthe blue light spectrum may be blocked or reduced in intensity and thetransmitted intensity of incident light in the ophthalmic system may beat least 80% for unblocked wavelengths.

As discussed previously, techniques for blue blocking are known. Theknown techniques to block blue light wavelengths include absorption,reflection, interference, or any combination thereof. As discussedearlier, according to one technique, a lens may be tinted/dyed with ablue blocking tint, such as BPI Filter Vision 450 or BPI Diamond Dye500, in a suitable proportion or concentration. The tinting may beaccomplished, for example, by immersing the lens in a heated tint potcontaining a blue blocking dye solution for some predetermined period oftime. According to another technique, a filter is used for blueblocking. The filter could include, for example, organic or inorganiccompounds exhibiting absorption and/or reflection of and/or interferencewith blue light wavelengths. The filter could comprise multiple thinlayers or coatings of organic and/or inorganic substances. Each layermay have properties, which, either individually or in combination withother layers, absorbs, reflects or interferes with light having bluelight wavelengths. Rugate notch filters are one example of blue blockingfilters. Rugate filters are single thin films of inorganic dielectricsin which the refractive index oscillates continuously between high andlow values. Fabricated by the co-deposition of two materials ofdifferent refractive index (e.g. SiO₂ and TiO₂), rugate filters areknown to have very well defined stop-bands for wavelength blocking, withvery little attenuation outside the band. The construction parameters ofthe filter (oscillation period, refractive index modulation, number ofrefractive index oscillations) determine the performance parameters ofthe filter (center of the stop-band, width of the stop band,transmission within the band). Rugate filters are disclosed in moredetail in, for example, U.S. Pat. Nos. 6,984,038 and 7,066,596, each ofwhich is by reference in its entirety. Another technique for blueblocking is the use of multi-layer dielectric stacks. Multi-layerdielectric stacks are fabricated by depositing discrete layers ofalternating high and low refractive index materials. Similarly to rugatefilters, design parameters such as individual layer thickness,individual layer refractive index, and number of layer repetitionsdetermine the performance parameters for multi-layer dielectric stacks.

Color balancing may comprise imparting, for example, a suitableproportion or concentration of blue tinting/dye, or a suitablecombination of red and green tinting/dyes to the color-balancingcomponent, such that when viewed by an external observer, the ophthalmicsystem as a whole has a cosmetically acceptable appearance. For example,the ophthalmic system as a whole may look clear or mostly clear.

FIG. 1A shows an ophthalmic system including a posterior blue blockingcomponent 101 and an anterior color-balancing component 102. Eachcomponent has a concave posterior side or surface 110, 115 and a convexanterior side or surface 120, 125. In system 100, the posterior blueblocking component 101 may be or include an ophthalmic component, suchas a single vision lens, wafer or optical pre-form. The single visionlens, wafer or optical pre-form may be, tinted or dyed to perform blue,blocking. The anterior color-balancing component 102 may comprise asurface cast layer, applied to the single vision lens, wafer or opticalpre-form according to known techniques. For example, the surface castlayer may be affixed or bonded to the single vision lens, wafer oroptical pre-form using visible or UV light, or a combination of the two.

The surface cast layer may be formed on the convex side of the singlevision lens, wafer or optical pre-form. Since the single vision lens,wafer or optical pre-form has been tinted or dyed to perform blueblocking, it may have a yellow or amber color that is undesirablecosmetically. Accordingly, the surface cast layer may, for example, betinted with a suitable proportion of blue tinting/dye, or a suitablecombination of red and green tinting/dyes.

The surface cast layer may be treated with color balancing additivesafter it is applied to the single vision lens, wafer or optical pre-formthat has already been processed to make it blue blocking. For example,the blue blocking single vision lens, wafer or optical pre-form with thesurface cast layer on, its convex surface may be immersed in a heatedtint pot which has the appropriate proportions and concentrations ofcolor balancing dyes in a solution. The surface cast layer will take upthe color balancing dyes from the solution. To prevent the blue blockingsingle vision lens, wafer or optical pre-form from absorbing any of thecolor balancing dyes, its concave surface may be masked or sealed offwith a dye resist, e.g. tape or wax or other coating. This isillustrated in FIG. 2, which shows an ophthalmic system 100 with a dyeresist 201 on the concave surface of the single vision lens, wafer oroptical pre-form 101. The edges of the single vision lens, wafer oroptical pre-form n-ay be left uncoated to allow them to becomecosmetically color adjusted. This may be important for negative focallenses having thick edges.

FIG. 1B shows another ophthalmic system 150 in which the anteriorcolor-balancing component 104 may be or include an ophthalmic component,such as a single vision or multi-focal lens, wafer or optical pre-form.The posterior blue blocking component 103 may be a surface cast layer.To make this combination, the convex surface of the color balancingsingle vision lens, wafer or optical pre-form may be masked with a dyeresist as described above, to prevent it taking up blue blocking dyeswhen the combination is immersed in a heated tint pot containing a blueblocking dye solution. Meanwhile, the exposed surface, cast layer willtake up the blue blocking dyes.

It should be understood that the surface cast layer could be used incombination with a multi-focal, rather than a single vision, lens, waferor optical pre-form. In addition, the surface cast layer could be usedto add power to a single vision lens, wafer or optical pre-form,including multi-focal power, thus converting the single vision lens,wafer or optical pre-form to a multi-focal lens, with either a lined orprogressive type addition. Of course, the surface cast layer could alsobe designed to add little or no power to the single vision lens, waferor optical preform.

FIG. 3 shows blue blocking and color balancing functionality integratedinto an ophthalmic component. More specifically, in ophthalmic lens 300,a portion 303 corresponding to a depth of tint penetration into anotherwise clear or mostly clear ophthalmic component 301 at a posteriorregion thereof may be blue blocking. Further, a portion 302,corresponding to a depth of tint penetration into the otherwise clear ormostly clear ophthalmic component 301 at a frontal or anterior regionthereof may be color balancing. The system illustrated in FIG. 3 may beproduced as follows. The ophthalmic component 301 may, for example,initially be a clear or mostly clear single vision or multi-focal lens,wafer or optical pre-form. The clear or mostly clear single vision ormulti-focal lens, wafer or optical pre-form may be tinted with a blueblocking tint while its front convex surface is rendered non-absorptive,e.g., by masking or coating with a dye resist as described previously.As a result, a portion 303, beginning at the posterior concave surfaceof the clear or mostly clear single vision or multi-focal lens, wafer oroptical pre-form 301 and extending inwardly, and having blue blockingfunctionality, may be created by tint penetration. Then, theanti-absorbing coating of the front convex surface may be removed. Ananti-absorbing coating may then be applied to the concave surface, andthe front convex surface and peripheral edges of the single vision ormulti-focal lens, wafer or optical preform may be tinted (e.g. byimmersion in a heated tint pot) for color balancing. The color balancingdyes will be absorbed by the peripheral edges and a portion 302beginning at the front convex surface and extending inwardly, that wasleft untinted due to the earlier coating. The order of the foregoingprocess could be reversed, i.e., the concave surface could first bemasked while the remaining portion was tinted for color balancing. Then,the coating, could be removed and a depth or thickness at the concaveregion left untinted by the masking could be tinted for blue blocking.

Referring now to FIG. 4, an ophthalmic system 400 may be formed using anin-mold coating. More specifically, an ophthalmic component 401 such asa single vision or multi-focal lens, wafer or optical pre-form which hasbeen dyed/tinted with a suitable blue blocking tint, dye or otheradditive may be color balanced via surface casting using a tintedin-mold coating 403. The in-mold coating 403, comprising a suitablelevel and/or mixtures of color balancing dyes, may be applied to theconvex surface mold (i.e., a mold, not shown, for applying the coating403 to the convex surface of the ophthalmic component 401). A colorlessmonomer 402 may be filled in and cured between the coating 403 andophthalmic component 401. The process of curing the monomer 402 willcause the color balancing in-mold coating to transfer itself to theconvex surface of the ophthalmic component 401. The result is a blueblocking ophthalmic system with a color balancing surface coating. Thein-mold coating could be, for example, an anti-reflective coating or aconventional hard coating.

Referring now to FIG. 5, an ophthalmic system 500 may comprise twoophthalmic components, one blue blocking and the other color balancing.For example, a first ophthalmic component 501 could be a back singlevision or concave surface multi-focal lens, wafer or optical pre-form,dyed/tinted with the appropriate blue blocking tint to achieve thedesired level of blue blocking. A second ophthalmic component 503 couldbe a front single vision or convex surface multi-focal lens, wafer oroptical pre-form, bonded or affixed to the back single vision or concavesurface multi-focal lens, wafer or optical pre-form, for example using aUV or visible curable adhesive 502. The front single vision or convexsurface multi-focal lens, wafer or optical pre-form could be renderedcolor balancing either before or after it was bonded with the backsingle vision or concave surface multi-focal lens, wafer or opticalpre-form. If after, the front single vision or convex surfacemulti-focal lens, wafer or optical pre-form could be rendered colorbalancing, for example, by techniques described above. For example, theback single vision or concave surface multi-focal lens, wafer or opticalpre-form may be masked or coated with a dye resist to prevent it takingup color balancing dyes. Then, the bonded back and front portions may betogether placed in a heated tint pot containing a suitable solution ofcolor balancing dyes, allowing the front portion to take up colorbalancing dyes.

Any of the above-described embodiments systems, may be combined with oneor more anti-reflective (AR) components. This is shown in FIG. 6, by wayof example, for the ophthalmic lenses 100 and 150 shown in FIGS. 1A and1B. In FIG. 6, a first AR component 601, e.g. a coating, is applied tothe concave surface of posterior blue blocking element 101, and a secondAR component 602 is applied to the convex surface of color balancingcomponent 102. Similarly, a first AR component 601 is applied to theconcave surface of posterior blue blocking component 103, and a secondAR component 602 is applied to the convex surface of color balancingcomponent 104.

FIGS. 7A-7C show further exemplary systems including a blue blockingcomponent and a color-balancing component. In FIG. 7A, an ophthalmicsystem 700 includes a blue blocking component 703 and a color balancingcomponent 704 that are formed as adjacent, but distinct, coatings orlayers on or adjacent to the anterior surface of a clear or mostly clearophthalmic lens 702. The blue blocking component 703 is posterior to thecolor-balancing component 704. On or adjacent to the posterior surfaceof the clear or mostly clear ophthalmic lens, an AR coating or otherlayer 701 may be formed. Another AR coating or layer 705 may be formedon or adjacent to the anterior surface of the color-balancing layer 704.

In FIG. 7B, the blue blocking component 703 and color-balancingcomponent 704 are arranged on or adjacent to the posterior surface ofthe clear or mostly clear ophthalmic lens 702. Again, the blue blockingcomponent 703 is posterior to the color-balancing component 704. An ARcomponent 701 may be formed on or adjacent to the posterior surface ofthe blue blocking component 703. Another AR component 705 may be formedon or adjacent to the anterior surface of the clear or mostly clearophthalmic lens 702.

In FIG. 7C, the blue blocking component 703 and the color-balancingcomponent 704 are arranged on or adjacent to the posterior and theanterior surfaces, respectively, of the clear ophthalmic lens 702.Again, the blue blocking component 703 is posterior to thecolor-balancing component 704. An AR component 701 may be formed on oradjacent to the posterior surface of the blue blocking component 703,and another AR component 705 may be formed on or adjacent to theanterior surface of the color-balancing component 704.

FIGS. 8A and 8B show an ophthalmic system 800 in which functionality toboth block blue light wavelengths and to perform color balancing may becombined in a single, component 803. For example, the combinedfunctionality component may block blue light wavelengths and reflectsome green and red wavelengths as well, thus neutralizing the blue andeliminating the appearance of a dominant color in the lens. The combinedfunctionality component 803 may be arranged on or adjacent to either theanterior or the posterior surface of a clear ophthalmic lens 802. Theophthalmic lens 800 may further include an AR component 801 on oradjacent to either the anterior or the posterior surface of the clearophthalmic lens 802.

To quantify the effectiveness of a co or balancing component, it may beuseful to observe light reflected and/or transmitted by a substrate ofan ophthalmic material. The observed light may be characterized by itsCIE coordinates to indicate the color of observed light; by comparingthese coordinates to the CIE coordinates of the incident, light, it ispossible to determine how much the color of the light was shifted due tothe reflection/transmission. White light is defined to have CIEcoordinates of (0.33, 0.33). Thus, the closer an observed, light's CIEcoordinates are to (0.33, 0.33), the “more white” it will appear to anobserver. To characterize the color shifting or balancing performed by alens, (0.33, 0.33) white light may be directed at the lens and the CIEof reflected and transmitted light observed. If the transmitted lighthas a CIE of about (0.33, 0.33), there will be no color shifting, anditems viewed through the lens will have a natural appearance, i.e., thecolor will not be shifted relative to items observed without the lens.Similarly, if the reflected light has a CIE of about (0.33, 0.33), thelens will have a natural cosmetic appearance, i.e., it will not appeartinted to an observer viewing a user of the lens or ophthalmic system.Thus, it, is desirable for transmitted and reflected light to have a CIEas close to (0.33, 0.33) as possible.

FIG. 9 shows a CIE, plot indicating the observed colors corresponding tovarious CIE coordinates. A reference point 900 indicates the coordinates(0.33, 0.33). Although the central region of the plot typically isdesignated as “white,” some light having CIE coordinates in this regioncan appear slightly tinted to a viewer. For example, light having CIEcoordinates, of (0.4, 0.4) will appear yellow to an observer. Thus, toachieve a color-neutral appearance in an ophthalmic system, it isdesirable for (0.33, 0.33) light (i.e., white light) that is transmittedand/or reflected by the system to have CIE coordinates as close to(0.33, 0.33) as possible after the transmission/reflection. The CIE plotshown in FIG. 9 will be used herein as a reference to show the colorshifts observed with various systems, though the labeled regions will beomitted for clarity.

Absorbing dyes may be included in the substrate material of anophthalmic lens by injection molding the dye into the substrate materialto produce lenses with specific light transmission and absorptionproperties. These dye materials can absorb at the fundamental peakwavelength of the dye or at shorter resonance wavelengths due to thepresence of a Soret band typically found in porphyrin materials.Exemplary ophthalmic materials include various glasses and polymers suchas CR-39®, TRIVEX®, polycarbonate, polymethylmethacrylate, silicone, andfluoropolymers, though other materials may be used and are known forvarious ophthalmic systems.

By way of example only, GENTEX dye material E465 transmittance andabsorbance is shown in FIGS. 10-11. The Absorbance (A) is related to thetransmittance (T) by the equation, A=log₁₀(1/T). In this case, thetransmittance is between 0 and 1 (0<T<1). Often transmittance is expressas a percentage, i.e., 0%<T<100%. The E465 dye blocks those wavelengthsless than 465 and is normally provided to block these wavelengths withhigh optical density (OD>4). Similar products are available to blockother wavelengths. For example, E420 from GENTEX blocks wavelengthsbelow 420 nm. Other exemplary dyes include porphyrins, perylene, andsimilar dyes that can absorb at blue wavelengths.

The absorbance at shorter wavelengths car be reduced by a reduction ofthe dye concentration. This and other dye materials can achieve atransmittance of ˜50% in the 430 nm region. FIG. 12 shows thetransmittance of a polycarbonate substrate with a dye concentrationsuitable for absorbing in the 430 nm range, and with some absorption inthe range of 420 nm-440 nm. This was achieved by reducing theconcentration of the dye and including the effects of a polycarbonatesubstrate. The rear surface is at this point not antireflection coated.

The concentration of dye also may affect the appearance and color shiftof an ophthalmic system. By reducing the concentration, systems withvarying degrees of color shift may be obtained. A “color shift” as usedherein refers to the amount by which the CIE coordinates of a referencelight change after transmission and/or reflection of the ophthalmicsystem. It also may be useful to characterize a system by the colorshift causes by the system due to the differences in various types oflight typically perceived as white (e.g., sunlight, incandescent light,and fluorescent light). It therefore may be useful to characterize asystem based on the amount by which the CIE coordinates of incidentlight are shifted when the light is transmitted and/or reflected by thesystem. For example, a system in which light with CIE coordinates of(0.33, 0.33) becomes light with a CIE of (0.30, 0.30) after transmissionmay be described as causing a color shift of (−0.03, −0.03), or, moregenerally, (±0.03, ±0.03). Thus the color shift caused by a systemindicates how “natural” light and viewed items appeal to a wearer of thesystem. As further described below, systems causing color shift of lessthan (±0.05, ±0.05) to (±0.02, ±0.02) have been achieved.

A reduction in short-wavelength transmission in an ophthalmic system maybe useful in reducing cell death due to photoelectric effects in theeye, such as excitation of A2E. It has been shown that reducing incidentlight at 430±30 nm by about 50% can reduce cell death by about 80%. See,for example, Janet R. Sparrow et al., “Blue light-absorbing intraocularlens and retinal pigment epithelium protection in vitro,” J. CataractRefract. Surg. 2004, vol. 30, pp. 873-78, the disclosure of which isincorporated by reference in its entirety. It is further believed thatreducing the amount of blue light, such as light in the 430-460 nmrange, by as little as 5% may similarly reduce cell death and/ordegeneration, and therefore prevent or reduce the adverse effects ofconditions such as atrophic age-related macular degeneration.

Although an absorbing dye may be used to block undesirable wavelengthsof light, the dye may produce a color tint in the lens as a side effect.For example, many blue-blocking ophthalmic lenses have a yellow coloringthat is often undesirable and/or aesthetically displeasing. To offsetthis coloring, a color balancing coating may be applied to one or bothsurfaces of a substrate including the absorbing dye therein.

Antireflection (AR) coatings (which are interference filters) arewell-established within the commercial ophthalmic coating industry. Thecoatings typically are a few layers, often less than 10, and typicallyare used to reduce the reflection from the polycarbonate surface to lessthan 1%. An example of such a coating on a polycarbonate surface isshown in FIG. 13. The color plot of this coating is shown in FIG. 14 andit is observed that the color is quite neutral. The total reflectancewas observed to be 0.21%. The reflected light was observed to have CIEcoordinates of (0.234, 0.075); the transmitted light had CIE coordinatesof (0.334, 0.336).

AR coatings may be applied to both surfaces of a lens or otherophthalmic device to achieve a higher transmittance. Such aconfiguration is shown in FIG. 15 where the darker line 1510 is the ARcoated polycarbonate and the thinner line 1520 is an uncoatedpolycarbonate substrate. This AR coating provides a 10% increase intotal transmitted light. There is some natural loss of light due toabsorption in the polycarbonate substrate. The particular polycarbonatesubstrate used for this example has a transmittance loss ofapproximately 3%. In the ophthalmic industry AR coatings generally areapplied to both surfaces to increase the transmittance of the lens.

In one embodiment, AR coatings or other color balancing films may becombined with an absorbing dye to allow for simultaneous absorption ofblue wavelength light, typically in the 430 nm region, and increasedtransmittance. As previously described, elimination of the light in the430 nm region alone typically results in a lens that has some residualcolor cast. To spectrally tailor the light to achieve a color neutraltransmittance, at least one of the AR coatings may be modified to adjustthe overall transmitted color of the light. This adjustment may beperformed on the front surface of the lens to create the following lensstructure:

Air (farthest from the user's eye)/Front convex lens coating/Absorbingophthalmic lens substrate/rear concave anti-reflection coating/Air(closest to the user's eye).

In such a configuration, the front coating may provide spectraltailoring to offset the color cast resulting from the absorption in thesubstrate in addition to the antireflective function typically performedin conventional lenses. The lens therefore may provide an appropriatecolor balance for both transmitted and reflected light. In the case oftransmitted light the color balance allows for proper color vision; inthe case reflected light the color balance may provide the appropriatelens aesthetics.

In some cases, a color balancing film may be disposed between two layersof other ophthalmic material. For example, a filter, AR film, or otherfilm may be disposed within an ophthalmic material. For example, thefollowing configuration may be used:

Air (farthest from the user's eye)/ophthalmic material/film/ophthalmicmaterial/air (closest to user's eye).

The color balancing film also may be a coating, such as a hardcoat,applied to the outer and/or inner surface of a lens. Otherconfigurations are possible. For example, referring to FIG. 3, anophthalmic system may include an ophthalmic material 301 doped with ablue-absorbing dye and one or more color balancing layers 302, 303. Inanother configuration, an inner layer 301 may be a color balancing layersurrounded by ophthalmic material 302, 303 doped with a blue-absorbingdye. Additional layers and/or coatings, such as AR coatings, may bedisposed on one or more surfaces of the system. It will be understoodhow similar materials and configurations may be used, for example in thesystems described with respect to FIGS. 4-8B.

Thus, optical films and/or coatings such as AR coatings may be used tofine-tune the overall spectral response of a lens having an absorbingdye. Transmission variation across the visible spectrum is well knownand varies as a function of the thickness and number of layers in theoptical coating. One or more layers can be used to provide the neededadjustment of the spectral properties.

In an exemplary system, color variation is produced by a single layer ofTiO₂ (a common AR coating material). FIG. 16 shows the spectraltransmittance of a 106 nm thick single layer of TiO₂. The color plot ofthis same layer is shown in FIG. 17. The CIE color coordinates (x, y)1710 shown for the transmitted light are (0.331, 0.345). The reflectedlight had CIE coordinates of (0.353, 0.251) 1720, resulting in apurplish-pink color.

Changing the thickness of the TiO₂ layer changes the color of thetransmitted light as shown in the transmitted spectra and color plot fora 134 nm layer, shown in FIGS. 18 and 19 respectively. In this system,the transmitted light exhibited CIE coordinates of (0.362, 0.368) 1910,and the reflected light had CIE coordinates of (0.209, 0.229) 1920. Thetransmission properties of various AR coatings and the prediction orestimation thereof are known in the art. For example, the transmissioneffects of an AR coating formed of a known thickness of an AR materialmay be calculated and predicted using various computer programs.Exemplary, non-limiting programs include Essential Macleod Thin FilmsSoftware available from Thin Film Center, Inc., TFCalc available fromSoftware Spectra, Inc., and FilmStar Optical Thin Film Softwareavailable from FTG Software Associates. Other methods may be used topredict the behavior of an AR coating or other similar coating or film.

In one embodiment, a blue-absorbing dye may be combined with a coatingor other film to provide a blue blocking, color balanced system. Thecoating may be an AR coating on the front surface that is modified tocorrect the color of the transmitted and/or reflected light. Thetransmittance and color plot of an exemplary AR coating are shown inFIGS. 20 and 21, respectively. FIGS. 22 and 23 show the transmittanceand color plot, respectively, for a polycarbonate substrate having ablue absorbing dye without an AR coating. The dyed substrate absorbsmost strongly in the 430 nm region, including some absorption in the420-440 nm region. The dyed substrate may be combined with anappropriate AR coating as illustrated in FIGS. 20-21 to increase theoverall transmittance of the system. The transmittance and color plotfor a dyed substrate having a rear AR coating are shown in FIGS. 24 and25, respectively.

An AR coating also may be applied to the front of an ophthalmic system(i.e., the surface farthest from the eye of a wearer of the system),resulting in the transmittance and color plot shown in FIGS. 26 and 27,respectively. Although the system exhibits a high transmission andtransmitted light is relatively neutral, the reflected light has a CIEof (0.249, 0.090). Therefore, to more completely color balance theeffects of the blue absorbing dye, the front AR coating may be modifiedto achieve the necessary color balance to produce a color neutralconfiguration. The transmittance and the color plot of thisconfiguration are shown in FIGS. 28 and 29 respectively. In thisconfiguration, both the transmitted and reflected light may be optimizedto achieve color neutrality. It may be preferred for the interiorreflected light to be about 6%. Should the reflectivity level beannoying to the wearer of the system, the reflection can be furtherreduced by way of adding an additional different absorbing dye into thelens substrate that would absorb a different wavelength of visiblelight. However, the design of this configuration achieves remarkableperformance and satisfies the need for a blue blocking, color balancedophthalmic system as described herein. The total transmittance is over90% and both the transmitted and reflected colors are quite close to thecolor neutral white point. As shown in FIG. 27, the reflected light hasa CIE of (0.334, 0.334), and the transmitted light has a CIE of (0.341,0.345), indicating little or no color shifting.

In some configurations, the front modified anti-reflection coating canbe designed to block 100% of the blue light wave length to be inhibited.However, this may result in a back reflection of about 9% to 10% for thewearer. This level of reflectivity can be annoying to the wearer. Thusby combining an absorbing dye into the lens substrate this reflectionwith the front modified anti-reflection coating the desired effect canbe achieved along with a reduction of the reflectivity to a level thatis well accepted by the wearer. The reflected light observed by a wearerof a system including one or more AR coatings may be reduced to 8% orless, or more preferably 3% or less.

The combination of a front and rear AR coating may be referred to as adielectric stack, and various materials and thicknesses may be used tofurther alter the transmissive and reflective characteristics of anophthalmic system. For example, the front AR coating and/or the rear ARcoating may be made of different thicknesses and/or materials to achievea particular color balancing effect. In some cases, the materials usedto create the dielectric stack may not be materials traditionally usedto create antireflective coatings. That is, the color balancing coatingsmay correct the color shift caused by a blue absorbing dye in thesubstrate without performing an antireflective function.

As discussed previously, filters are another technique for blueblocking. Accordingly, any of the blue blocking components discussedcould be or include or be combined with blue blocking filters. Suchfilters may include rugate filters, interference filters, band-passfilters, band-block filters, notch filters or dichroic filters.

In one embodiment, one of more of the above-disclosed blue-blockingtechniques may be used in conjunction with other blue-blockingtechniques. By way of example only, a lens or lens component may utilizeboth a dye/tint and a rugate notch filter to effectively block bluelight.

Any of the above-disclosed structures and techniques may be employed inan ophthalmic system to perform blocking of blue light wavelengths at ornear 400-460 nm. For example, in embodiments the wavelengths of bluelight blocked may be within a predetermined range. In embodiments, therange may be 430 nm±30 nm. In other embodiments, the range may be 430nm±20 nm. In still other embodiments, the range may be 430 nm±10 nm. Theterm “X±Y nm” means inhibiting wavelengths of light from X nm minus Y nmto X nm plus Y nm. For example, “430 nm±10 nm” means inhibitingwavelengths of light from 420 nm to 440 nm. In embodiments, theophthalmic system may limit transmission of blue wavelengths within theabove-defined ranges to substantially 90% of incident wavelengths. Inother embodiments, the ophthalmic system may limit transmission of theblue wavelengths within the above-defined ranges to substantially 80% ofincident wavelengths. In other embodiments, the ophthalmic system maylimit transmission of the blue wavelengths within the above-definedranges to substantially 70% of incident wavelengths. In otherembodiments, the ophthalmic system may limit transmission of the bluewavelengths within the above-defined ranges to substantially 60% ofincident wavelengths. In other embodiments, the ophthalmic system maylimit transmission of the blue wavelengths within the above-definedranges to substantially 50% of incident wavelengths. In otherembodiments, the ophthalmic system may limit transmission of the bluewavelengths within the above-defined ranges to substantially 40% ofincident wavelengths. In still other embodiments, the ophthalmic systemmay limit transmission of the blue wavelengths within the above-definedranges to substantially 30% of incident wavelengths. In still otherembodiments, the ophthalmic system may limit transmission of the bluewavelengths within the above-defined ranges to substantially 20% ofincident wavelengths. In still other embodiments, the ophthalmic systemmay limit transmission of the blue wavelengths within the above-definedranges to substantially 10% of incident wavelengths. In still otherembodiments, the ophthalmic system may limit transmission of the bluewavelengths within the above-defined ranges to substantially 5% ofincident wavelengths. In still other embodiments, the ophthalmic systemmay limit transmission of the blue wavelengths within the above-definedranges to substantially 1% of incident wavelengths. In still otherembodiments, the ophthalmic system may limit transmission of the bluewavelengths within the above-defined ranges to substantially 0% ofincident wavelengths. Stated otherwise, attenuation by the ophthalmicsystem of the electromagnetic spectrum at wavelengths in theabove-specified ranges may be at least 10%; or at least 20%; or at least30%; or at least 40%; or at least 50%; or at least 60%; or at least 70%;or at least 80%; or at least 90%; or at least 95%; or at least 99%; orsubstantially 100%.

In some cases it may be particularly desirable to filter a relativelysmall portion of the blue spectrum, such as the 400 nm-460 nm region.For example, it has been found that blocking too much of the bluespectrum can interfere with scotopic vision and circadian rhythms.Conventional blue blocking ophthalmic lenses typically block a muchlarger amount of a wide range of the blue spectrum, which can adverselyaffect the wearer's “biological clock” and have other adverse effects.Thus, it may be desirable to block a relatively narrow range of the bluespectrum as described herein. Exemplary systems that may filter arelatively small amount of light in a relatively small range includesystem that block or absorb 5-50%, 5-20%, and 5-10% of light having awavelength of 400 nm-460 nm, 410 nm-450 nm, and 420 nm-440 nm.

In one embodiment, the ophthalmic system, e.g., a corneal inlay,selectively inhibits light within a range of blue light wavelengths. Theinhibited range of blue light wavelengths can be any range within,including the endpoints of, 400 nm to 500 nm. Thus, the inhibitedwavelengths can be, for example, 400 to 500 nm, 400 to 475 nm, 400 nm to470 nm, 400 to 450 nm, 400 to 460 nm, 410 to 450 nm, 420 to 440 nm, orabout 430 nm. In another embodiment, the size of the inhibited range ofblue light wavelengths, as measured by full-width at half-maximum(FWHM), is no more than about 100 nm, about 75 nm, about 60 nm, about 50nm, about 40 nm, about 30 nm, about 20 nm, about 10 nm, or about 5 nm.

In one embodiment, the inhibited range of blue light wavelengthsincludes 430 nm because blue light having a wavelength of 430 nm isknown to excite chromophore A2E. In another embodiment, the inhibitedrange of Hue light wavelengths, includes and/or peaks at one or moresingularly damaging wavelengths. By selectively filtering particularwavelength ranges, the ophthalmic systems described herein can optimizethe trade-off between achieving protection from harmful wavelengths andmaintaining, acceptable color cosmetics, color perception, overall lighttransmission, photopic vision, scotopic vision, color vision, and/orcircadian rhythms.

To selectively inhibit light within a range of blue light wavelengths,the ophthalmic system transmits less than about 90%, less than about80%, less than about 70%, less than about 60%, or less than about 50%,of light within the range of blue light wavelengths. In one embodiment,the system transmits about 0% to about 90% or increments therein, oflight within the range of blue light wavelengths. In another embodiment,the system transmits about 20% to about 30% of light within the range ofblue light wavelengths.

The term “increments therein” is meant to explicitly enumerate allvalues and ranges from the lower value to the upper value in incrementsof any measurable degree of precision. For example, if a variable isfrom 0 to 90 or increments therein, values and ranges such as 0 to 80,30 to 75, 22 to 68, 43 to 51, 32, 30.3, etc. are expressly contemplatedas part of this invention.

At the same time as wavelengths of blue light are selectively blocked asdescribed above, at least 80%, at least 85%, at least 90%, or at least95% of other portions of the visual electromagnetic spectrum may betransmitted by the ophthalmic system. Stated otherwise, attenuation bythe ophthalmic system of the electromagnetic spectrum at wavelengthsoutside the blue light spectrum, e.g. wavelengths other than those in arange around 430 nm may be 20% or less, 15% or less, 10% or less, and inother embodiments, 5% or less.

Additionally, some embodiments may further block ultra-violet radiationthe UVA and UVB spectral bands as well as infra-red radiation withwavelengths greater than 700 nm.

Any of the above-disclosed ophthalmic system may be incorporated into anarticle of eyewear, including externally-worn eyewear such aseyeglasses, sunglasses, goggles or contact lenses. In such eyewear,because the blue-blocking component of the systems is posterior to thecolor balancing component, the blue-blocking component will always becloser to the eye than the color-balancing component when the eyewear isworn. The ophthalmic system may also be used in such articles ofmanufacture as surgically implantable intra-ocular lenses.

Several embodiments use a film to block the blue light. The film in anophthalmic or other system may selectively inhibit at least 5%, at least10%, at least 20%, at least 30%, at least 40%, and/or at least 50% ofblue light within the 400 nm-460 nm range. As used herein, a film“selectively inhibits” a wavelength range if it inhibits at least sometransmission within the range, while having little or ho effect ontransmission of visible wavelengths outside the range. The film, and/ora system incorporating the film may be color balanced to allow for beingperception by an observer and/or user as colorless. Systemsincorporating a film may have a scotopic luminous transmission of 85% orbetter of visible light, and further allow someone looking through thefilm or system to have mostly normal color vision.

FIG. 30 shows an exemplary embodiment. A film 3002 may be disposedbetween two layers or regions of one or more base materials 3001, 3003.As further described herein, the film may contain a dye that selectivelyinhibits certain wavelengths of light. The base material or materialsmay be any material suitable for a lens, ophthalmic system, window, orother system in which the film may be disposed.

The optical transmission characteristic of an exemplary film is shown inFIG. 31 where about 50% of blue light in the range of 430 nm±10 nm isblocked, while imparting minimal losses on other wavelengths within thevisible spectrum. The transmission shown in FIG. 31 is exemplary, and itwill be understood that for many applications it may be desirable toselectively inhibit less than 50% of blue light, and/or the specificwavelengths inhibited may vary. It is believed that in many applicationscell death may be reduced or prevented by blocking less than 50% of bluelight. For example, it may be preferred to selectively inhibit about40%, more preferably about 30%, more preferably about 20%, morepreferably about 10%, and more preferably about 5% of light in the400-460 nm range. Selectively inhibiting a smaller amount of light mayallow for prevention of damage due to high-energy light, while beingminimal enough that the inhibition does not adversely affect scotopicvision and/or circadian cycles in a user of the system.

FIG. 32 shows a film 3201 incorporated into an ophthalmic lens 3200,where it is sandwiched between layers of ophthalmic material 3202, 3203.The thickness of the front layer of ophthalmic material is, by way ofexample only, in the range of 200 microns to 1,000 microns.

Similarly, FIG. 33 shows an exemplary system 3300, such as an automotivewindshield. A film 3301 may be incorporated into the system 3300, whereit is sandwiched between layers of base material 3302, 3303. Forexample, where the system 3300 is an automotive windshield, the basematerial 3302, 3303 may be windshield glass as is commonly used. It willbe understood that in various other systems, including visual, display,ophthalmic, and other systems, different base materials may be usedwithout departing from the scope of the present invention.

In an embodiment, a system may be operated in an environment where therelevant emitted visible light has a very specific spectrum. In, such aregime, it may be desirable to tailor a film's filtering effect tooptimize the light transmitted, reflected, or emitted by the item. Thismay be the case, for example, where the color of the transmitted,reflected, or emitted light is of primary concern. For example, when afilm is used in or with a camera flash or flash filter, it, may bedesirable for the perceived color of the image or print to be as closeto true color as possible. As another example, a film may be used ininstrumentation for observing the back of a patient's eye for disease.In such a system, it may be important for the film not to interfere withthe true and observed color of the retina. As another example, certainforms of artificial lighting may benefit from a wavelength-customizedfilter utilizing the inventive film.

In an embodiment, the inventive film may be utilized within aphotochromatic, electrochromic, or changeable tint ophthalmic lens,window or automotive windshield. Such a system may allow for protectionfrom UV light wavelengths, direct sunlight intensity, and blue lightwavelengths in an environment where the tinting is not active. In thisembodiment the film's blue light wavelengths protective attributes maybe effective regardless of whether the tinting is active.

In an embodiment, a film may allow for selective inhibition of bluelight while being color balanced and will have an 85% or greaterscotopic luminous transmission of visible light. Such a film may beuseful for lower light transmission uses such as driving glasses orsport glasses, and may provide increased visual performance due toincreased contrast sensitivity.

For some applications, it may be desirable for a system to selectivelyinhibit blue light as described herein, and have a luminous transmissionof less than about 85%, typically about 80-85%, across the visiblespectrum. This may be the case where, for example, a base material usedin the system inhibits more light across all visible wavelengths due toits higher index of refraction. As a specific example, high index (e.g.,1.7) lenses may reflect more light across wavelengths leading to aluminous transmission less than 85%.

To avoid, reduce, or eliminate problems present in conventionalblue-blocking systems, it may be desirable to reduce, but not eliminate,transmission of phototoxic blue light. The pupil of the eye responds tothe photopic retinal illuminance, in trolands, which is the product ofthe incident flux with the wavelength-dependent sensitivity of theretina and the projected area of the pupil. A filter placed in front ofthe retina, whether within the eye, as in an intraocular lens, attachedto the eye, as in a contact lens or corneal replacement, or otherwise inthe optical path of the eye as in a spectacle lens, may reduce the totalflux of light to the retina and stimulate dilation of the pupil, andthus compensate for the reduction in field illuminance. When exposed toa steady luminance in the field the pupil diameter generally fluctuatesabout a value that increases as the luminance falls.

A functional relationship between pupil area and field illuminancedescribed by Moon and Spencer, J. Opt. Soc. Am. v. 33, p. 260 (1944)using the following equation for pupil diameter:

d=4.9−3 tan h(Log(L)+1)  (0.1)

where d is in millimeters and L is the illuminance in cd/m². FIG. 34Ashows pupil diameter (mm) as a function of field illuminance (cd/m²).FIG. 34B shows pupil area (mm²) as a function of field illuminance.

The illuminance is defined by the international CIE standards as aspectrally weighted integration of visual sensitivity over wavelength:

L=K _(m) ∫L _(e,λ) V _(λ) dλphotopic

L′=K′ _(m) ∫L _(e,λ) V′ _(λ) dλscotopic  (0.2)

where K_(m)′ is equal to 1700.06 lm/W for scotopic (night) vision,Km=683.2 lm/W for photopic (day) vision and the spectral luminousefficiency functions Vλ and Vλ′ define the standard photopic andscotopic observers. The luminous efficiency functions Vλ and Vλ′ areillustrated in, e.g., FIG. 9 of Michael Kalloniatis aid Charles Luu,“Psychophysics of Vision,” available athttp://webvision.med.utah.edu/Phych1.html, last visited Aug. 8, 2007,which is incorporated by reference herein.

Interposition of an absorptive ophthalmic element in the form of anintraocular, contact, or spectacle lens reduces the illuminanceaccording to the formula:

L=K _(m) ∫T _(λ) L _(e,λ) V _(λ) dλphotopic

L′=K′ _(m) ∫T _(λ) L _(e,λ) V′ _(λ) dλscotopic  (0.3)

where Tλ is the wavelength-dependent transmission of the opticalelement. Values for the integrals in equation 1.3 normalized to theunfiltered illuminance values computed from equation 1.2 for each of theprior-art blue blocking lenses are shown in Table I.

TABLE I Reference Figure Photopic Ratio Scotopic Ratio Unfiltered 1.0001.000 Pratt '430 0.280 0.164 Mainster 2005/0243272 0.850 0.775 PresentSystem 35 0.996 0.968 Present System 36 (solid line) 0.993 0.947 PresentSystem 37 0.978 0.951

Referring to Table I, the ophthalmic filter according to Pratt reducesscotopic sensitivity by 83.6% of its unfiltered value, an attenuationthat will both degrade night vision and stimulate pupil dilationaccording to equation 1.1. The device described by Mainster reducesscotopic flux by 22.5%, which is less severe than the Pratt device butstill significant.

In contrast, a film as disclosed herein may partially attenuates violetand blue light using absorptive or reflective ophthalmic elements whilereducing the scotopic illuminance by no wore than 15% of its unfilteredvalue. Surprisingly, such systems were found to selectively inhibit adesired region of blue light, while having little to no effect onphotopic and scotopic vision.

In an embodiment, perylene (C₂₀H₁₂, CAS #198-55-0) is incorporated intoan ophthalmic device at a concentration and thickness sufficient toabsorb about two-thirds of the light at its absorption maximum 437 nm.The transmission spectrum of this device is shown in FIG. 35. Peryleneprovides selective filtering of high energy visible blue lightwavelengths in the range of 430 nm±20 nm. More, specifically peryleneprovides a notch at 420 nm. Perylene can also provide increased contrastsensitivity. The loading level of, perylene dye is selected to minimizeany effect on the scoptopic vision, bio-rhythms, color vision, and pupildilation of the wearer. The change in illuminance that results from thisfilter is only, about 3.2% for scotopic viewing conditions and about0.4% under photopic viewing conditions, as displayed in Table I.Increasing the concentration or thickness of perylene in the devicedecreases the transmission at each wavelength according to Beer's law.FIG. 36 shows the transmission spectrum of a device with a peryleneconcentration 2.27 times higher than that for FIG. 35. Although thisdevice selectively blocks more of the phototoxic blue light than thedevice in FIG. 35, it reduces scotopic illuminance by less than 6% andphotopic illuminance by less than 0.7%. Note that reflection has beenremoved from the spectra in FIGS. 35 and 36 to show only the effect ofabsorption by the dye.

Dyes other than perylene may have strong absorption in blue or roughlyblue wavelength ranges and little or no absorbance in other regions ofthe visible spectrum. Examples of such dyes porphyrin, in FIG. 46,include porphyrin, coumarin, and acridine based molecules which may beused singly or in combination to give transmission that is reduced, butnot eliminated, at 400 nm-460 nm. The methods and systems describedherein therefore may use similar dyes based on other molecularstructures at concentrations that mimic the transmission spectra ofperylene, porphyrin, coumarin, and acridine.

The insertion of dye into the optical path may be accomplished bydiverse methods familiar to hose practiced in the art of opticalmanufacturing. The dye or dyes may be incorporated directly into thesubstrate, added to a polymeric coating, imbibed into the lens,incorporated in a laminated structure that includes a dye-impregnatedlayer, or as a composite material with dye-impregnated microparticles.

According to another embodiment, a dielectric coating that is partiallyreflective in the violet and blue spectral regions and antireflective atlonger wavelengths may be applied. Methods for designing appropriatedielectric optical filters are summarized in textbooks such as AngusMcLeod, Thin Film Optical Filters (McGraw-Hill:NY) 1989. An exemplarytransmission spectrum for a six-layer stack of SiO₂ and ZrO₂ is shown inFIG. 37. Referring again to Table I, it is seen that this optical filterblocks phototoxic blue and violet light while reducing scotopicilluminance by less than 5% and photopic illuminance by less than 3%.

Although many conventional blue blocking technologies attempt to inhibitas much blue light as possible, current research suggests that in manyapplications it may be desirable to inhibit a relatively small amount ofblue light. For example, to prevent undesirable effects on scotopicvision, it may be desirable for an ophthalmic system to inhibit onlyabout 30% of blue (i.e., 380-500 nm) wavelength light, or morepreferably only about 20% of blue light, more preferably about 10%, andmore preferably about 5%. It is believed that cell death may be reducedby inhibiting as little as 5% of blue light, while this degree of bluelight reduction has little or no effect on scotopic vision and/orcircadian behavior of those using the system.

As used herein, a film that selectively inhibits blue light is describedas inhibiting an amount of light measured relative to the base systemincorporating the film. For example, an ophthalmic system may use apolycarbonate or other similar base for a lens. Materials typically usedfor such a base may inhibit a various amount of light at visiblewavelengths. If a blue-blocking film is added to the system, it mayselectively inhibit 5%, 10%, 20%, 30%, 40%, and/or 50% of all bluewavelengths, as measured relative to the amount of light that would betransmitted at the same wavelength(s) in the absence of the film.

The methods and devices disclosed herein may minimize, and preferablyeliminate, the shift in color perception that results fromblue-blocking. The color perceived by the human visual system resultsfrom neural processing of light signals that fall on retinal pigmentswith different spectral response characteristics. To describe colorperception mathematically, a color space is constructed by integratingthe product of three wavelength-dependent color matching functions withthe spectral irradiance. The result is three numbers that characterizethe perceived color. A uniform (L*, a*, b*) color space, which has beenestablished by the Commission Internationale de L′eclairage (CIE), maybe used to characterize perceived colors, although similar calculationsbased on alternative color standards are familiar to those practiced inthe art of color science and may also be used. The (L*, a*, b*) colorspace defines brightness on the L* axis and color within the planedefined by the a* and b* axes. A uniform color space such as thatdefined by this CIE standard may be preferred for computational andcomparative applications, since the Cartesian distances of the space areproportional to the magnitude of perceived color difference between twoobjects. The use of uniform color spaces generally is recognized in theart, such as described in Wyszecki and Stiles, Color Science: Conceptsand Methods, Quantitative Data and Formulae (Wiley: New York) 1982.

An optical design according to the methods and systems described hereinmay use a palette of spectra that describe the visual environment. Anon-limiting example of this is the Munsell matte color palette, whichis comprised of 1,269 color tiles that have been established bypsychophysical experiments to be just noticeably different from eachother. The spectral irradiance of these tiles is measured under standardillumination conditions. The array of color coordinates corresponding toeach of these tiles illuminated by a D65 daylight illuminant in (L*, a*,b*) color space is the reference for color distortion and is shown inFIG. 38. The spectral irradiance of the color tiles is then modulated bya blue-blocking filter and a new set of color coordinates is computed.Each tile has a perceived color that is shifted by an amountcorresponding to the geometric displacement of the (L*, a*, b*)coordinates. This calculation has been applied to the blue-blockingfilter of Pratt, where the average color distortion is 41 justnoticeable difference (JND) units in (L*, a*, b*) space. The minimumdistortion caused by the Pratt filter is 19 JNDs, the maximum is 66, andthe standard deviation is 7 JNDs. A histogram of the color shifts forall 1,269 color tiles is shown in FIG. 39A (top).

Referring now to FIG. 39B, the color shift induced by the Mainsterblue-blocking filter has a minimum value of 6, an average of 19, amaximum of 34, and a standard deviation of 6 JNDs.

Embodiments using perylene dye at two concentrations or the reflectivefilter described above may have substantially smaller color shifts thanconventional devices whether measured as an average, minimum, or maximumdistortion, as illustrated in Table II. FIG. 40 shows a histogram ofcolor shifts for a perylene-dyed substrate whose transmission spectrumis shown in FIG. 35. Notably, the shift across all color tiles wasobserved to be substantially lower and narrower than those forconventional devices described by Mainster, Pratt, and the like. Forexample, simulation results showed (L*, a*, b*) shifts as low as 12 and20 JNDs for exemplary films, with average shifts across all tiles as lowas 7-12 JNDs.

TABLE II Std. Avg. δ Min. δ Max. δ Deviation δ Reference Figure(L*,a*,b*) (L*,a*,b*) (L*,a*,b*) (L*,a*,b*) Pratt 41 19 66 12 Mainster19 6 34 6 Present System 35 7 2 12 2 Present System 36 12 4 20 3 PresentSystem 37 7 2 12 2

In an embodiment, a combination of reflective and absorptive elementsmay filter harmful blue photons while maintaining relatively highluminous transmission. This may allow a system to avoid or reduce pupildilation, preserve or prevent damage to night vision, and reduce colordistortion. An example of this approach combines the dielectric stacksshown in FIG. 37 with the perylene dye, of FIG. 35, resulting in thetransmission spectrum shown in FIG. 41. The device was observed to havea photopic transmission of 97.5%, scotopic transmission o 93.2%, and anaverage color shift of 11 JNDs. The histogram summarizing colordistortion of this device for the Munsell tiles in daylight is shown inFIG. 42.

In another embodiment, an ophthalmic filter is external to the eye, forexample a spectacle lens, goggle, visor, or the like. When a traditionalfilter is used, the color of the wearer's face when viewed by anexternal observer may be tinted by the lens, i.e., the facial colorationor skin tone typically is shifted by a blue-blocking lens when viewed byanother person. This yellow discoloration that accompanies blue lightabsorption is often not cosmetically desirable. The procedure forminimizing this color shift is identical to that describe above for theMunsell tiles, with the reflectance of the wearer's skin beingsubstituted for those of the Munsell color tiles. The color of skin is afunction of pigmentation, blood flow, and the illumination conditions. Arepresentative series of skin reflectance spectra from subjects ofdifferent races is shown in FIGS. 43A-B. An exemplary skin reflectancespectrum for a Caucasian subject is shown, in FIG. 44. The (L*, a*, b*)color coordinates of this skin in daylight (D65) illumination are (67.1,18.9, 13.7). Interposition of the Pratt blue-blocking filter changesthese color coordinates to (38.9, 17.2, 44.0), a shift of 69 JND units.The Mainster blue-blocking filter shifts the color coordinates by 17 JNDunits to (62.9, 13.1, 29.3). By contrast, a perylene filter as describedherein causes a color shift of only 6 JNDs, or one third that of theMainster filter. A summary of the cosmetic color shift of an exemplaryCaucasian skin under daylight illumination using various blue-blockingfilters is shown in Table III. The data shown in Table I refer arenormalized to remove any effect caused by a base material.

TABLE III Reference Figure L* a* b* δ(L*,a*,b*) Skin 14-15 67 19 14 0Pratt 39 17 44 69 Mainster 63 13 29 17 Present System 15 67 17 19 6Present System 36 67 15 23 10 Present System 37 67 17 19 6

In an embodiment, an illuminant may be filtered to reduce but noteliminate the flux of blue light to the retina. This may be accomplishedwith absorptive or reflective elements between the field of view and thesource of illumination using the principles described herein. Forexample, an architectural window may be covered with a film thatcontains perylene so that the transmission spectrum of the windowmatches that shown in FIG. 35. Such a filter typically would not inducepupil dilation when compared to an uncoated window, nor would it causeappreciable color shifts when external daylight passes through it. Bluefilters may be used on artificial illuminants such as fluorescent,incandescent, arc, flash, and diode lamps, displays, and the like.

Various materials may be used in making films. Two such exemplarymaterials are Poly Vinyl Alcohol (PVA) and Poly Vinyl Butyral (PVB). Inthe case of PVA film it may be prepared by partial or completehydrolysis of polyvinyl acetate to remove the acetate groups. PVA film,may be desirable due to beneficial film forming, emulsifying, andadhesive properties. In addition, PVA film has high tensile strength,flexibility, high temperature stability, and provides an excellentoxygen barrier.

PVB film may be prepared from a reaction of polyvinyl alcohol inbutanal. PVB may be suitable for applications that require highstrength, optical clarity, flexibility and toughness. PVB also hasexcellent film forming and adhesive properties.

PVA, PVB, and other suitable films may be extruded, cast from asolution, spin coated and then cured, or dip coated and then cured.Other manufacturing methods known in the art also may be used There areseveral ways of integrating the dyes needed to create the desiredspectral profile of the film. Exemplary dye-integration methods includevapor deposition, chemically cross linked within the film, dissolvedwithin small polymer micro-spheres and then integrated within the film.Suitable dyes are commercially available from companies includingKeystone, BPI & Phantom.

Most dyeing of spectacle lenses is done after the lens has been shippedfrom the manufacturer. Therefore, it may be desirable to incorporate ablue-absorbing dye during the manufacture of the lens itself. To do so,the filtering and color balancing dyes may be incorporated into a hardcoating and/or an associated primer coating which promotes adhesion ofthe hard coating to the lens material. For example, a primer coat andassociated hard coat are often added to the top of a spectacle lens orother ophthalmic system at the end of the manufacturing process toprovide additional durability and scratch resistance for the finalproduct. The hard coat typically is an outer-most layer of the system,and may be placed on the front, back, or both the front and backsurfaces of the system.

FIG. 47 shows an exemplary system having a hard coating 4703 and itsassociated adhesion-promoting primer coat 4702. Exemplary hard coatings,and adhesion promoting primer coating are available from manufacturerssuch as Tokuyama, UltraOptics, SDC, PPG, and LTI.

In one embodiment, both a blue blocking dye and a color balancing dyemay be included in the primer coating 1802. Both the blue blocking andcolor balancing dyes also may be included in the hard coating 1803. Thedyes need not be included in the same coating layer. For example, a blueblocking dye may be included in the hard coating 1803, and a colorbalancing dye included in the primer coating 1802. The color balancingdye may be included in the hard coating 1803 and the blue blocking dyein the primer coating 1802.

Primer and hard coats may be deposited using methods known in the art,including spin-coating, dip-coating, spray-coating, evaporation,sputtering, and chemical vapor deposition. The blue blocking and/orcolor balancing dyes to be included in each layer may be deposited atthe same time as the layer, such as where a dye is dissolved in a liquidcoating material and the resulting mixture applied to the system. Thedyes also may be deposited in a separate process or sub-process, such aswhere a dye is sprayed onto a surface before the coat is cured or driedor applied.

A hard coat and/or primer coat may perform functions and achievebenefits described herein with respect to a film. Specifically, the coator coats may selectively inhibit blue light, while maintaining desirablephotopic vision, scotopic vision, circadian rhythms, and phototoxicitylevels. Hard coats and/or primer coats as described herein also may beused in an ophthalmic system incorporating a film as described herein,in any and various combinations. As a specific example, an ophthalmicsystem may include a film that selectively inhibits blue light and ahard coat that provides color correction.

The selective filter can also provide increased contrast sensitivity.Such a system functions to selectively filter harmful invisible andvisible light while having minimal effect on photopic vision, scotopicvision, color vision, and/or circadian rhythms while maintainingacceptable or even improved contrast sensitivity. In certainembodiments, the end, residual color of the device to which theselective filter is applied is mostly colorless, and in otherembodiments where a mostly clear residual color is not required theresidual color can be yellowish. Preferably, the yellowness of theselective filter is unobjectionable to the subjective individual wearer.Yellowness can be measured quantitatively using a yellowness index suchas ASTM E313-05. Preferably, the selective filter has a yellowness indexthat is no more than 50, 40, 35, 30, 25, 23, 20, 15, 10, 9, 7, or 5.

The system could include selective light wavelength filteringembodiments such as windows, automotive windshields, light bulbs, flashbulbs, fluorescent lighting, LED lighting, television, computermonitors, etc. Any light that impacts the retina can be selectivelyfiltered by the system. The system can be enabled, by way of exampleonly, a film comprising a selective filtering dye or pigment, a dye orpigment component added after a substrate is fabricated, a dye componentthat is integral with the fabrication or formulation of the substratematerial, synthetic or non-synthetic pigment such as melanin, lutein, orzeaxanthin, selective filtering dye or pigment provided as a visibilitytint (having one or more colors) as in a contact lens, selectivefiltering dye or pigment provided in an ophthalmic scratch resistantcoating (hard coat), selective filtering dye or pigment provided in anophthalmic anti-reflective coat, selective light wave length filteringdye or pigment provided in a hydrophobic coating, an interferencefilter, selective light wavelength filter, selective light wavelengthfiltering dye or pigment provided in a photochromic lens, or selectivelight wavelength filtering dye or pigment provided in a matrix of alight bulb or tube. The system can selectively filter out one specificrange of wavelengths, or multiple specific ranges of wavelengths, butnot filter out wavelengths evenly across the visible spectrum.

Those skilled in the art will know readily how to provide the selectivelight wavelength filter to the substrate material. By way of exampleonly, the selective filter can be: imbibed, injected, impregnated, addedto the raw materials of the substrate, added to the resin prior topolymerization, layered within in the optical lens by way of a filmcomprising the selective filter dye or pigments.

The system may utilize a proper concentration of a dye and or pigmentsuch as, by way of example only, perylene, porphrin or theirderivatives. Refer to FIG. 48 to observe varying concentration ofperylene and the functional ability to block wavelengths of light ataround 430 nm. The transmission level can be controlled by dyeconcentration. Other dye chemistries allow adjustment of the absorptionpeak positions.

Perylene at appropriate concentration levels in an appropriate basematerial provides balance in photopic, scotopic, circadian, andphototoxicity ratios while maintaining a mostly colorless appearance:

TABLE V Photopic Scotopic Phototoxicity Circadian Ratio- Ratio-V′λ Ratio(Bλ) Ratio (M′λ) Reference Vλ (%) (%) (%) (%) Unfiltered 100 100 100 100Polycarbonate-undyed 88 87 86 74 Pratt 28 16 4 7 Mainster 86 78 39 46Mainster (−20 nm shift) 86 83 63 56 Mainster (+20 nm shift) 84 68 15 32HPOO dye (2x) 88 81 50 62 HPOO dye (x) 88 84 64 63 HPOO (x/2) 87 84 7266 HPOO (x/4) 39 87 79 71

Increases in contrast sensitivity are observed with appropriateconcentration of perylene. See Example 2, Table VI. The family ofperylene based dyes or pigments are exemplary dyes. When such a dye isused, depending upon the embodiment or application, the dye may beformulated such that it is bonded molecularly or chemically to thesubstrate or a coating that is applied to the substrate such that thedye does not leach out. By way of example only, applications of thiswould be for use with contact lenses, IOLs, corneal in-lays, cornealon-lays, etc.

Selective filters can be combined to hinder other target wavelengths asscience discovers other visible light wavelength hazards.

In one embodiment, a contact lens is comprised of a perylene dyeformulated such that it will not leach out of the contact lens material.The dye is further formulated such that it provides a tint having ayellow cast. This yellow cast allows for the contact lens to have whatis known as a handling tint for the wearer. The perylene dye or pigmentfurther provides the selective filtering as shown by FIG. 48. Thisfiltering provides retinal protection and enhanced contrast sensitivitywithout compromising in any meaningful way one's photopic vision,scotopic vision, color vision, or circadian rhythms.

In the case of the inventive embodiment of a contact lens the dye orpigment can be imparted into the contact lens by way of example only, byimbibing, so that it is located within a central 10 mm diameter or lesscircle of the contact lens, preferably within 6-8 mm diameter of thecenter of the contact lens coinciding with the pupil of the wearer. Inthis embodiment the dye or pigment concentration which providesselective light wavelength filtering is increased to a level thatprovides the wearer with an increase in contrast sensitivity (as opposeto without wearing the contact lens) and without compromising in anymeaningful way (one or more, or all of) the wearer's photopic vision,scotopic vision, color vision, or circadian rhythms.

Preferably, an increase in contrast sensitivity is demonstrated by anincrease in the user's Functional Acuity Contrast Test (FACT) score ofat least about 0.1, 0.25, 0.3, 0.5, 0.7, 1, 1.25, 1.4, or 1.5. Withrespect to the wearer's photopic vision, scotopic vision, color vision,and/or circadian rhythms, the ophthalmic system preferably maintains oneor all of these characteristics to within 15%, 10%, 5%, or 1% of thecharacteristic levels without the ophthalmic system.

In another inventive embodiment that utilizes a contact lens the dye orpigment is provided that causes a yellowish tint that it is located overthe central 5-7 mm diameter of the contact lens and wherein a secondcolor tint is added peripherally to that of the central tint. In thisembodiment the dye concentration which provides selective lightwavelength filtering is increased to a level that provides the wearervery good contrast sensitivity and once again without compromising inany meaningful way (one or more, or all of) the wearer's photopicvision, scotopic vision, color vision, or circadian rhythms.

In still another inventive embodiment that utilizes a contact lens thedye or pigment is provided such that it is located over the fulldiameter of the contact lens from approximately one edge to the otheredge. In this embodiment the dye concentration which provides selectivelight wavelength filtering is increased to a level that provides thewearer very good contrast sensitivity and once again withoutcompromising in any meaningful way (one or more, or all of) the wearer'sphotopic vision, scotopic vision, color vision, or circadian rhythms.

When various, inventive embodiments are used in or on human or animaltissue the dye is formulated in such a way to chemically bond to theinlay substrate material thus ensuring it will not leach out in thesurrounding corneal tissue. Methods for providing a chemical hook thatallow for this bonding are well known within the chemical and polymerindustries.

In still another inventive embodiment an intraocular lens includes aselective light wavelength filter that has a yellowish tint, and thatfurther provides the wearer improved contrast sensitivity withoutcompromising in any meaningful way (one or more, or all of) the wearer'sphotopic vision, scotopic vision, color vision, or circadian rhythms.When the selective filter is utilized on or within an intra-ocular lensit is possible to increase the level of the dye or pigment beyond thatof a spectacle lens as the cosmetics of the intra-ocular lens areinvisible to someone looking at the wearer. This allows for the abilityto increase the concentration of the dye or pigment and provides evenhigher levels of improved contrast sensitivity without compromising inany meaningful way (one or more or all of) the wearer's photopic vision,scotopic vision, color vision, or circadian rhythms.

In still another embodiment, a spectacle lens includes a selective lightwave length filter comprising a dye having perylene wherein the dye'sformulation provides a spectacle lens that has a mostly colorlessappearance. And furthermore that provides the wearer with improvedcontrast sensitivity without compromising in any meaningful way (one ormore, or all of) the wearer's photopic vision, scotopic vision, colorvision, or circadian rhythms. In this particular embodiment, the dye orpigment is imparted within a film that is located within or on thesurface, of the spectacle lens.

In another embodiment, the system can be a corneal inlay. Similar to theother blue-blocking ophthalmic systems described herein, the cornealinlay can provide protection to a plurality of ocular structures withinthe eye while maintaining acceptable color cosmetics, color perception,overall light transmission, photopic vision, scotopic vision, colorvision, and/or circadian rhythms. The corneal inlay can provide propercorneal metabolism. Furthermore, the corneal inlay can also include apinhole effect to improve clear near-point vision and increase depth offocus. In some embodiments, the corneal inlay can also correctrefractive errors including, but not limited to, higher orderaberration, lower order aberration, myopia, hyperopia, astigmatism,and/or presbyopia.

The selective filtering of blue light wavelengths can be achieved by anymaterial known in the art including, but not limited to, one or moreblue-blocking dyes as described above. Suitable dyes include, but arenot limited to, perylene, porphyrin, coumarin, acridine, derivativesthereof, or compounds that mimic the transmission spectra thereof.

One or more blue-blocking dyes can be added to the bio-compatiblematerial during or after processing by way of any technique known in theart of optical manufacturing. For example, a dye can be incorporateddirectly into the substrate, added to a polymeric coating, imbibed intothe inlay, incorporated in a laminated structure that includes adye-impregnated layer, or as a composite material with dye-impregnatedmicroparticles.

Regardless of incorporation technique, the dye should be prevented fromleaching out into the surrounding cornea. For example, the dye can becovalently bound to the substrate material. Alternatively, the dye canbe imbibed, dispersed, or dissolved in the substrate and encapsulated ina cross-linked polymer to inhibit diffusion of the dye out of thecorneal inlay. Optionally, a sealing layer can be placed on the cornealimplant. A sealing layer can be, for example, a sealer-like coating, athin polymer layer, or a layer that is laminated within the cornealinlay comprising the dye(s).

In one embodiment, the corneal inlay further comprises a UV-inhibitingmaterial, e.g., a UV-blocking dye. UV-inhibiting materials arewell-known in the art and are used in many ophthalmic lens applications.In one embodiment, an ultraviolet-inhibiting material blocks at leastabout 90%, preferably at least about 95%, or at least about 99% of lightat wavelengths of less than about 400 nm, preferably about 280 nm toabout 400 nm or increments therein, such as about 280 nm to about 315nm.

In one embodiment, the corneal inlay can provide a pinhole effect toenhance the depth perception and near-point focus of the wearer. Inanother embodiment, the pinhole effect can be created by any ophthalmicsystem described herein, e.g., a spectacle lens, contact lens,intraocular lens, corneal inlay, and corneal onlay. The pinhole effectcan be created by providing a central zone, which allows a hightransmission of visible light, and a peripheral region, which limits thetransmission of visible light. The central zone and peripheral regionact as a static shutter or lens stop. “Static” means fixed, i.e., notdynamic. The pinhole effect can be, created by, for example, an opaque,frosted, crazed, or defocused peripheral region with a centraltransmissive, un-frosted, un-crazed, or focused zone (FIG. 49B). Thediameter of the central zone is preferably about 2.5 mm to about 1 mm orincrements therein, or about 1.5 mm. The central zone can be circular,or it can be any in the interior of the inlay. For example, the centralzone can be other shape a symmetrical, asymmetrical, geometric, curved,or irregular shape. Preferably the central zone is circular and iscentered in the inlay.

The pinhole effect can increase depth of focus and enhance near-focusvision for a presbyopic or emerging-presbyopic individual. A pinholecorneal inlay can be implanted in one or both eyes of a patient. In oneembodiment, a pinhole corneal inlay is implanted in a monocular manner,i.e., in only one eye of a patient. In this embodiment, the pinholecorneal inlay is preferably implanted into the non-dominant eye. Acorneal inlay without a pinhole effect, such as a blue-blocking cornealinlay described herein, can be implanted in the dominant eye.Preferably, both eyes receive a corneal inlay comprising theblue-blocking and/or UV-blocking features described herein.

In one embodiment of the pinhole corneal inlay, the central zoneincludes a blue-blocking component. For example, the central zoneincludes one or more dyes that selectively inhibit light within a rangeof blue light wavelengths as described above. This embodimentsurprisingly both protects the retina from harmful blue lightwavelengths while also enhancing depth perception. The pinhole effectdepends on the difference in contrast between the central zone and theperipheral region. One might predict that including a dye in the centralzone would decrease the contrast differential between the central zoneand the peripheral region and thus eliminate the pinhole effect and itsaccompanying enhancement of depth perception. However, the inventorshave discovered that even with the blue-blocking dye, the contrastdifferential can be sufficiently maintained to achieve the pinholeeffect.

The central zone and the peripheral region can be designed to maintain acontrast differential of at least about 60%, at least about 65%, atleast about 70%, at least about 80%, or at least about 90%. In oneembodiment, the contrast differential is about 60% to about 80% orincrements therein, such as about 60% to about 65%, and about 70% toabout 80%. The transmission of visible light through the center zone canbe, for example, about 80% to about 95% or increments herein about 85%to about 95%, or about 90%. The transmission of visible light throughthe peripheral region can be, for example, about 15% to about 30% orincrements therein, about 20% to about 30%, or about 20% to about 25%.The transmission of visible light can be measured by, e.g., averagetransmission or preferably by luminous transmission.

Proper corneal metabolism can be achieved by selecting bio-compatiblematerials, properly positioning the corneal inlay, and/or providingmicro-apertures as described below. The inventive corneal inlay can bemade of various bio-compatible materials including, but not limited to,a non-hydrogel, microporous, ophthalmic perfluoropolyether material; apolyvinylidene fluoride material; or any other suitable plastic materialknown in the field of ophthalmics.

The corneal inlay can include a plurality of micro-apertures (FIG. 49A).The micro-apertures can be created during or after processing of thebio-compatible material. The micro-apertures allow for proper cornealmetabolism including fluids, nutrients, solutes, and extracellulartransport. The micro-apertures can be formed throughout the entirety ofthe corneal inlay, or any portion thereof. For example, in the pinholecorneal inlay described below, the micro-apertures can be formed in theperipheral region and/or in the central zone. In one embodiment, themicro-apertures are formed only in the peripheral region.

The diameter of the corneal inlay can be about 3.5 mm to about 7 mm orincrements therein, such as about 4 mm. The thickness of the corneal canbe about 5 microns to about 15 microns or increments therein, such asabout 10 microns. For embodiment including micro-apertures, themicro-apertures have an average diameter of about 1 micron to 100microns or increments therein, such as about 50 microns to about 75microns.

The corneal inlay can be implanted into the eye by any known methodologyand/or the methodology described herein. For example, the cornea can beprepared to receive the corneal inlay by sectioning the cornea to createa corneal flap having the proper thickness, diameter, and locationrelative to the pupil and the limbus. The corneal flap can be createdby, e.g., a mechanical microkeratome or femtosecond laser. Proceduresfor creating a corneal flap are well-known in the art and are used withLASIK procedures as well as other lamellar corneal surgical procedures.

In one embodiment, the flap is not removed from the cornea, but isfolded out of the way as the corneal inlay is properly positioned intoplace. Once the corneal inlay is in place, the corneal flap is unfoldedand positioned over the corneal inlay. The diameter of the corneal flapcan be larger than that of the corneal inlay thus allowing for thecornea to seal and heal around the periphery of the corneal inlay.

The method for implanting the corneal inlay can further include a stepof performing Laser-Assisted in situ Keratomileusis (LASIK) to alter theshape of the cornea. For example, after creating the corneal flap, aLASIK procedure can be performed to alter, improve, and/or correct arefractive error of the patient. A LASIK procedure can also be used tosculpt a more defined and deeper recess in the cornea, to facilitatepositioning of the corneal inlay. The corneal inlay can be positionedwithin a recess, and the corneal flap can be repositioned over thecorneal inlay. In this way, a thicker conical inlay can be implanted.

The corneal inlay may correct a lower order aberration or a higher orderaberration as described below. Any of these corrections includes acomplete correction of, or any improvement to, the refractive error ofthe wearer.

In one embodiment, the corneal inlay can correct a refractive error suchas myopia, hyperopia, or astigmatism. The correction of refractive errorcan be achieved by one or more features including, but not limited to,curving the peripheral region of the corneal inlay, thickening theperipheral region of the conical inlay, altering the diameter of thecorneal inlay (FIG. 49C). The corneal inlay can cause refractive changesand/or reshape the external corneal curvature.

In another embodiment, the corneal inlay can correct a refractive error,including presbyopia, by way of diffraction. In this embodiment, thecorneal inlay includes a diffractive design pattern (FIG. 49E) on anexternal surface of the corneal inlay or embedded in the interior of thecorneal inlay.

In yet another embodiment, the central zone of the corneal inlayincludes a plurality of pixel-like index of refractive changes (FIG.49D) to impart an index change. Index changes can provide sphericalrefractive changes and/or correct for higher order aberration. Higherorder aberrations are refractive error aberrations other than myopia,hyperopia, regular astigmatism, and presbyopia. One embodiment is amethod of correcting for higher order aberration by performing awavefront measurement of the wearer, then correcting the wavefrontmeasurement by implanting a corneal inlay including a plurality of indexchanges. This corneal inlay can be created, e.g., by curing the polymerof the corneal inlay (or a layer of modifiable polymer material affixedto the corneal inlay) to provide a predictable and desired localizedindex of refraction changes. In another embodiment, the index changescan be imparted in situ by a final cure of the corneal inlay (either ofthe entire material structure, or a layer of material that is presenton, or located inside of, the corneal inlay) after the corneal inlay isimplanted within the cornea. The final cure can be performed by, e.g., aspecified and targeted light radiation cure, occurring almostsimultaneously in a mostly closed loop manner to refine and perfect thehigher order aberration correction. Thus, a method of correcting higherorder aberration can include performing an iterative wavefront analysiswhile curing the corneal inlay to impart an index change.

The wavefront analysis and in situ curing method described above canalso be used to correct for lower order aberrations such as myopia,hyperopia, regular astigmatism, and presbyopia. Wavefront analysis andphoto-curing polymers using visible and non-visible light sources areboth well-known in the art. To determine the refractive error of thepatient, one or more of a wavefront aberrometer, an auto-refractor,and/or a manual refractor can be used. The methods can include one, two,or more refining, steps achieve the final optical correction of thecorneal inlay when using the inventive closed loop method previouslydescribed.

Any one or more of the above-described features—inhibiting UV light;inhibiting a range of blue light wavelengths; static shuttering;correcting refractive error; correcting lower order aberration includingmyopia, hyperopia, regular astigmatism, and presbyopia; and correctinghigher order aberration—can be used with any embodiment describedherein.

EXAMPLES Example 1

A polycarbonate lens having an integral film with varying concentrationsof blue-blocking dye was fabricated and the transmission spectrum ofeach lens was measured as shown in FIG. 45. Perylene concentrations of35, 15, 7.6, and 3.8 ppm (weight basis) at a lens thickness of 2.2 mmwere used. Various metrics calculated for each lens are shown in TableIV, with references corresponding to the reference numerals in FIG. 45.Since the selective absorbance of light depends primarily on the productof the dye concentration and coating thickness according to Beer's law,it is believed that comparable results are achievable using a hard coatand/or primer coat in conjunction with or instead of a film.

TABLE IV Photopic Scotopic Circadian Phototoxicity Lens Ref Ratio (Vλ)Ratio (V′λ) Ratio (M′λ) Ratio (Bλ) Unfiltered 100.0% 100.0% 100.0%100.0% light (no lens) Polycarbonate 4510  87.5%  87.1%  74.2%  85.5%Lens (no dye) 3.8 ppm (2.2 mm) 4520  88.6%  86.9%  71.0%  78.8% 7.6 ppm(2.2 mm) 4530  87.0%  84.1%  65.9%  71.1%  15 ppm (2.2 mm) 4540  88.3% 83.8%  63.3%  63.5%  35 ppm (2.2 mm) 4550  87.7%  80.9%  61.5%  50.2%

With the exception of the 35 ppm dyed lens, all the lenses described inTable IV and FIG. 45 include a UV dye typically used in ophthalmic lenssystems to inhibit UV wavelengths below 380 nm. The photopic ratiodescribes normal vision, and is calculated as the integral of the filtertransmission spectrum and Vλ (photopic visual sensitivity) divided bythe integral of unfiltered light and this same sensitivity curve. Thescotopic ratio describes vision in dim lighting conditions, and iscalculated as the integral of the filter transmission spectrum and V′λ(scotopic visual sensitivity) divided by the integral of unfilteredlight and this same sensitivity curve. The circadian ratio describes theeffect of light on circadian rhythms, and is calculated as the integralof the filter transmission spectrum and M′λ (melatonin suppressionsensitivity) divided by the integral of unfiltered light and this samesensitivity curve. The phototoxicity ratio describes damage to the eyecaused by exposure to high-energy light, and is calculated as theintegral of the filter transmission and the Bλ (phakic UV-bluephototoxicity) divided by the integral of unfiltered light and this samesensitivity curve. Response functions used to calculate these valuescorrespond to those disclosed in Mainster and Sparrow, “How Much BlueLight Should an IOL Transmit?” Br. J. Ophthalmol., 2003, v. 87, pp.1523-29, Mainster, “Intraocular Lenses Should Block UV Radiation andViolet but not Blue Light,” Arch. Ophthal., v. 123, p. 550 (2005), andMainster, “Violet and Blue Light Blocking Intraocular Lenses:Photoprotection vs. Photoreception”, Br. J. Ophthalmol, 2006, v. 90, pp.784-92. For some applications, a different phototoxicity curve isappropriate but the methodology for calculation is the same. Forexample, for intraocular lens 000 applications, the aphakicphototoxicity curve should be used. Moreover, new phototoxicity curvesmay be applicable as the understanding of the phototoxic lightmechanisms improves.

As shown by the exemplary data described above, a system may selectivelyinhibit blue light, specifically light in the 400 nm-460 nm region,while still providing a photopic luminous transmission of at least about85% and a phototoxicity ration of less than about 80%, more preferablyless than about 70%, more preferably less than about 60%, and morepreferably less than about 50%. As previously described, a photopicluminous transmission of up to 95% or more, also may be achievable usingthe techniques described herein.

The principles described herein may be applied to varied illuminants,filters, and skin tones, with the objective of filtering some portion ofphototoxic blue light while reducing pupil dilation, scotopicsensitivity, color distortion through the ophthalmic device, andcosmetic color of an external ophthalmic device from the perspective ofan observer that views the person wearing the device on their face.

Several embodiments of the invention are specifically illustrated and/ordescribed herein. However, it will be appreciated that modifications andvariations of the invention are covered by the above teachings andwithin the purview of the appended claims without departing from thespirit and intended scope of the invention. For examples, although themethods and systems described herein have been described using examplesof specific dyes, dielectric optical filters, skin tones, andilluminants, it will be understood that alternative dyes, filters, skincolors, and illuminants may be used.

Example 2

Nine patients were tested for contrast sensitivity using dyeconcentrations of DC and 2× against a clear filter as a control. 7 ofthe 9 patients showed overall improved contrast sensitivity according tothe Functional Acuity Contrast Test (FACT). See Table VI:

TABLE VI Contrast sensitivity test for dye samples with loadings of Xand 2X. Test was done February, 2007 at Vision Associaates in Havre deGrace, Maryland by Dr. Andy Ishak. The test consisted of 10 patients,each tested with two filters, using the FACT contrast sensitivitytesting process 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1Dotted Dotted Dotted Dotted Dotted Solid 2 A B C D E A 3 NO Lt Dk NO LtDk NO Lt Dk NO Lt Dk NO Lt Dk NO Lt Dk 4 1 JP 5 6 6 6 6 6 6 6 6 5 5 5 44 4 7 6 7 5 ↑1 ↑1 0 0 0 0 0 0 0 0 ↓−1 0 6 2 BJ 6 7 7 7 7 7 7 6 6 3 3 3 43 3 7 5 6 7 ↑1 ↑1 0 0 ↓−1 ↓−1 0 0 ↓−1 ↓−1 ↓−2 ↓−1 8 3 JB 8 8 8 6 7 7 5 57 5 4 5 1 3 5 9 9 9 9 0 0 ↑1 ↑1 0 ↑2 ↓−1 0 ↑2 ↑4 0 0 10 4 AW 7 7 8 6 7 86 5 7 5 5 6 4 4 5 6 7 7 11 0 ↑1 ↑1 ↑2 ↓−1 ↑1 0 ↑1 0 ↑1 ↑1 ↑1 12 5 LL 7 66 6 6 5 2 5 3 1 4 4 1 3 2 6 6 6 13 ↓−1 ↓−1 0 ↓−1 ↑3 ↑1 ↑3 ↑3 ↑2 ↑1 0 014 6 TS 7 9 9 8 9 9 8 9 8 6 7 7 4 7 5 5 8 8 15 ↑2 ↑2 ↑1 ↑1 ↑1 0 ↑1 ↑1 ↑3↑1 ↑3 ↑3 16 7 KS 6 6 6 5 5 5 5 4 4 3 2 2 2 1 1 5 6 5 17 0 0 0 0 ↓−1 ↓−1↓−1 ↓−1 ↓−1 ↓−1 ↑1 0 18 9 DS 5 6 6 5 7 7 5 6 6 3 5 5 1 4 4 5 6 7 19 ↑1↑1 ↑2 ↑2 ↑1 ↑1 ↑2 ↑2 ↑3 ↑3 ↑1 ↑2 20 10  NK 9 9 9 21 0 0 22 Tot 51 55 5649 54 54 44 46 47 31 35 37 21 29 29 59 62 64 23 Delta 4 5 5 5 2 3 4 6 88 3 5 24 Avg 6.4 6.9 7.0 6.1 6.8 6.8 5.5 5.8 5.9 3.9 4.4 4.6 2.6 3.6 3.66.6 6.9 7.1 25 Delta ↑0.5 ↑0.6 ↑0.6 ↑0.6 ↑0.3 ↑0.4 ↑0.5 ↑0.8 ↑1.0 ↑1.0↑0.3 ↑0.6 26 27 Better (↑) 4 5 4 4 3 4 3 4 4 5 4 3 28 Worse (↓) 1 1 0 13 2 2 1 2 2 2 1 1 2 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 1 SolidSolid Solid Solid Number 2 B C D E Tot Better Worse 3 NO Lt Dk NO Lt DkNO Lt Dk NO Lt Dk Diff (↑) (↓) 4 1 JP 6 6 7 6 7 6 5 5 5 5 2 4 5 0 ↑1 ↑10 0 0 ↓−3 ↓−1 −1 4 3 6 2 BJ 7 7 7 8 7 7 6 6 6 4 5 5 7 0 0 ↓−1 ↓−1 0 0 ↑1↑1 −5 4 8 8 3 JB 7 9 9 8 8 8 5 6 9 4 4 5 9 ↑2 ↑2 0 0 ↑1 ↑4 0 ↑1 19 10 110 4 AW 6 6 7 5 6 7 3 4 6 3 5 6 11 0 ↑1 ↑1 ↑2 ↑1 ↑3 ↑2 ↑3 21 15 1 12 5LL 6 5 6 2 6 4 3 2 3 2 4 2 13 ↓−1 0 ↑4 ↑2 ↓−1 0 ↑2 0 16 9 6 14 6 TS 6 88 7 8 8 4 5 5 4 4 4 15 ↑2 ↑2 ↑1 ↑1 ↑1 ↑1 0 0 27 17 0 16 7 KS 5 5 4 2 4 42 2 3 1 1 1 17 0 ↓−1 ↑2 ↑2 0 ↑1 0 0 −1 4 7 18 9 DS 6 6 6 5 5 5 3 4 4 2 33 19 0 0 0 0 ↑1 ↑1 ↑1 ↑1 25 16 0 20 10  NK 9 9 8 7 7 8 4 5 7 4 6 8 21 0↓−1 0 ↑1 ↑1 ↑3 ↑2 ↑4 10 5 1 22 Tot 58 61 62 50 58 57 35 39 48 29 34 3823 Delta 3 4 8 7 4 13 5 9 111 24 Avg 6.4 6.8 6.9 5.6 6.4 6.3 3.9 4.3 5.33.2 3.8 4.2 5.6 25 Delta ↑0.3 ↑0.4 ↑0.9 ↑0.8 ↑0.4 ↑1.4 ↑0.6 ↑1.0 26 27Better (↑) 2 4 5 5 5 6 5 5 28 Worse (↓) 1 2 1 1 1 0 1 1 Comments: 1Patient number 8 data was dropped. This patient was a 60 yr old,diabetic, with cataracts 2 Patient 10 was tested in one eye only 3 Theterms dotted and solid refer to the two eyes of the patients, how theywere shown on test result forms 4 The headings “NO”, refer to lenseswith clear filter, ie control. The terms Lt and Dk refer to the dyeloading in the tested filters. 5 For each patient, the top line is theiractual score. Second line is the difference with filters versus nonfiltered “control” 6 Boxes marked with UP ARROW showed improvement,boxes with DOWN ARROW showed negative results. 7 Total scores (line 22)add up how all patients scored on a specific test column 8 TotalDifference (column 33) shows how each patient scored overall on all 5test columns (A-E) for both eyes

What is claimed is:
 1. An ophthalmic system comprising: a visible lightwavelength filter that selectively blocks between 5 and 50% of light ina range of blue light wavelengths that includes 430 nm; wherein thefilter is placed within corneal tissue, and wherein the yellowness indexof the system is no more than 15.0.
 2. The system of claim 1, whereinthe system includes a porphyrin dye.
 3. The system of claim 1, whereinthe system includes a dye with a Soret band.
 4. The system of claim 1,wherein the system includes coumarin.
 5. The system of claim 1, whereinthe system includes acridine based molecules.
 6. The system of claim 1,wherein the system includes a compound that mimics the transmissionspectra of a Soret band.
 7. The system of claim 1, wherein theyellowness index of the system is no more than
 10. 8. The system ofclaim 1, wherein the yellowness index of the system is no more than 9.9. The system of claim 1, wherein the yellowness index of the system isno more than
 7. 10. The system of claim 1, wherein the yellowness indexof the system is no more than
 5. 11. The system of claim 1, wherein thefilter is applied directly into corneal tissue.
 12. The system of claim1, wherein the filter is placed on human tissue.
 13. The system of claim12, wherein the filter includes a chemical bond so the filter will notleach out in the surrounding corneal tissue.